JP5686137B2 - Method for producing fluororubber composition - Google Patents

Description

(Cross-reference to related applications)
This application is a reference to 35 U.S. of US Provisional Patent Application No. 61 / 377,009, filed Aug. 25, 2010, which is incorporated herein by reference in its entirety. S. C. Claim a benefit under §119 (e).

  The present invention relates to a method for producing a fluororubber composition that gives a crosslinked product having excellent mechanical properties at high temperatures.

  Fluororubber is known to have excellent chemical resistance, oil resistance, heat resistance, and good compression set resistance at high temperatures, but mechanical properties at high temperatures such as hot strength and hot elongation In recent years, for example, when a fluororubber crosslinked product is used in a high temperature environment exceeding 100 ° C., it is required to have excellent durability not only in heat resistance but also in mechanical properties at high temperature. .

  For example, from the viewpoint of improving compression set, a composition as shown in Patent Document 1 has been proposed, but since room temperature elongation is small, it is expected that thermal elongation will be further reduced. Further, Patent Document 2 discloses an improvement in hot elongation, but it is not a physical property that can withstand even in a severer use environment. As an improvement in strength at high temperature, as shown in Patent Document 3, a combination of fluororubber and a fluorine-containing thermoplastic elastomer is exemplified, but since room temperature elongation is small, the elongation at heat is further reduced. is expected.

JP-A-60-55050 JP 2008-18496 A Japanese Patent Laid-Open No. 06-25500

  An object of this invention is to provide the manufacturing method of the fluororubber composition which provides the crosslinked material which was excellent not only in heat resistance but in the mechanical property at the time of high temperature.

That is, in the present invention, in the presence of the organic amine compound (C1) and / or acid acceptor (C2), the maximum temperature Tm of 80 ° C. of the kneaded product during kneading of the fluororubber (A) and the carbon black (B) is previously determined. The present invention relates to a method for producing a fluororubber composition, which is kneaded at a temperature of ˜220 ° C. and discharged at that temperature.
In other words, the present invention is a method for producing a fluororubber composition, which comprises the fluororubber (A) and the fluoroamine (A) in the presence of an organic amine compound (C1) and / or an acid acceptor (C2). A fluororubber comprising a step of kneading carbon black (B), wherein the maximum temperature Tm of the kneaded product at the time of kneading and the maximum temperature of the kneaded product at the time of discharge are 80 to 220 ° C. The present invention relates to a method for producing a composition.

The carbon black (B) is preferably carbon black having a nitrogen adsorption specific surface area (N ₂ SA) of 5 to 180 m ² / g and a dibutyl phthalate (DBP) oil absorption of 40 to 180 ml / 100 g.

  As the fluororubber (A), vinylidene fluoride copolymer rubber, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer rubber, or tetrafluoroethylene / propylene copolymer rubber is used. Aging property) and oil resistance are preferable from the viewpoint of good.

  It is preferable that the compounding quantity of carbon black (B) with respect to 100 mass parts of fluororubbers (A) is 5-50 mass parts.

  The compounding amount of the organic amine compound (C1) and / or the acid acceptor (C2) with respect to 100 parts by mass of the fluororubber (A) is preferably 0.01 to 10 parts by mass.

  The fluororubber composition has a shear elastic modulus G ′ (1) at a dynamic strain of 1% when uncrosslinked in a dynamic viscoelasticity test (measurement frequency: 1 Hz, measurement temperature: 100 ° C.) using a rubber process analyzer (RPA). %) And the difference δG ′ (G ′ (1%) − G ′ (100%)) between the shear elastic modulus G ′ (100%) at a dynamic strain of 100% is 120 kPa or more and 3,000 kPa or less. preferable.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the fluororubber composition which provides not only heat resistance but the crosslinked material excellent also in the mechanical physical property at the time of high temperature can be provided.

  In the method for producing the fluororubber composition of the present invention, the fluororubber (A) and the carbon black (B) are previously mixed in the presence of the organic amine compound (C1) and / or the acid acceptor (C2). The maximum temperature of the kneaded material is Tm 80 ° C. to 220 ° C., and the mixture is kneaded under the conditions of discharging at that temperature to obtain a fluororubber composition. That is, a fluororubber composition is obtained through a step of kneading the fluororubber (A) and the carbon black (B) in the presence of the organic amine compound (C1) and / or the acid acceptor (C2). In this step, the maximum temperature Tm of the kneaded product during kneading is controlled to 80 to 220 ° C., and the maximum temperature is controlled to 80 to 220 ° C. even when the kneaded product is discharged. The production method of the present invention is a step of kneading the fluororubber (A) and the carbon black (B) in the presence of the organic amine compound (C1) and / or the acid acceptor (C2). In addition, as long as it includes a process in which the maximum temperature Tm of the kneaded product at the time of kneading and the maximum temperature of the kneaded product at the time of discharge are 80 to 220 ° C., other steps may be included.

  First, each component will be described.

(A) Fluoro rubber As the fluoro rubber (A) used in the present invention, for example, tetrafluoroethylene (TFE), vinylidene fluoride (VdF), and formula (1):
CF ₂ = CF-R _f ^a (1)
(Wherein R _f ^a is —CF ₃ or —OR _f ^b (R _f ^b is a perfluoroalkyl group having 1 to 5 carbon atoms)) (for example, hexafluoropropylene ( HFP), perfluoro (alkyl vinyl ether) (PAVE) and the like, and preferably includes a structural unit derived from at least one monomer selected from the group consisting of.

  From another viewpoint, as the fluoro rubber, non-perfluoro fluoro rubber and perfluoro fluoro rubber are preferable.

  Non-perfluoro fluororubbers include vinylidene fluoride (VdF) fluororubber, tetrafluoroethylene (TFE) / propylene (Pr) fluororubber, tetrafluoroethylene (TFE) / propylene (Pr) / vinylidene fluoride (VdF). ) Series fluororubber, ethylene / hexafluoropropylene (HFP) series fluororubber, ethylene (Et) / hexafluoropropylene (HFP) / vinylidene fluoride (VdF) series fluororubber, ethylene (Et) / hexafluoropropylene (HFP) / Tetrafluoroethylene (TFE) -based fluororubber, fluorosilicone-based fluororubber, or fluorophosphazene-based fluororubber, etc., and these may be used alone or in any combination within a range not impairing the effects of the present invention. It is possible. Among these, VdF-based fluororubber, TFE / Pr-based rubber, and TFE / Pr / VdF-based rubber are more preferable from the viewpoint of good heat aging resistance and oil resistance.

  In the VdF rubber, the VdF repeating unit is preferably 20 mol% or more and 90 mol% or less of the total number of moles of the VdF repeating unit and the repeating unit derived from another comonomer, preferably 40 mol% or more, 85 More preferably, it is at most mol%. A more preferred lower limit is 45 mol%, a particularly preferred lower limit is 50 mol%, and a more preferred upper limit is 80 mol%.

The comonomer in the VdF rubber is not particularly limited as long as it is copolymerizable with VdF. For example, TFE, HFP, PAVE, chlorotrifluoroethylene (CTFE), trifluoroethylene, trifluoropropylene, Tetrafluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, hexafluoroisobutene, vinyl fluoride, iodine-containing fluorinated vinyl ether, general formula (2)
CH ₂ = CFR _f (2)
(Wherein R _f is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms) fluorine-containing monomers such as fluorine-containing monomers; ethylene (Et), propylene (Pr), alkyl Non-fluorine-containing monomers such as vinyl ether, monomers that give a crosslinkable group (cure site), and reactive emulsifiers are included. One or more of these monomers and compounds are combined. Can be used.

  As the PAVE, perfluoro (methyl vinyl ether) (PMVE) and perfluoro (propyl vinyl ether) (PPVE) are more preferable, and PMVE is particularly preferable.

Further, as the PAVE, _{formula: CF 2 = CFOCF 2 OR f} c
(In the formula, R _f ^c is a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, a cyclic perfluoroalkyl group having 5 to 6 carbon atoms, or 2 to 3 carbon atoms containing 1 to 3 oxygen atoms. 6 linear or branched perfluorooxyalkyl groups), CF ₂ = CFOCF ₂ OCF ₃ , CF ₂ = CFOCF ₂ OCF ₂ CF ₃ , or CF ₂ = CFOCF ₂ OCF ₂ CF ₂ OCF ₃ is preferably used.

The fluorine-containing monomer represented by the above formula (2) is preferably a monomer in which R _f is a linear fluoroalkyl group, and a monomer in which R _f is a linear perfluoroalkyl group. More preferred. R _f preferably has 1 to 6 carbon atoms. As the fluorine-containing monomer represented by the above formula (2), CH ₂ = CFCF ₃ , CH ₂ = CFCF ₂ CF ₃ , CH ₂ = CFCF ₂ CF ₂ CF ₃ , CH ₂ = CFCF ₂ CF ₂ CF ₂ Examples thereof include CF ₃ , among which 2,3,3,3-tetrafluoropropylene represented by CH ₂ ═CFCF ₃ is preferable.

  Examples of the VdF rubber include VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / CTFE copolymer, VdF / CTFE / TFE copolymer, VdF / PAVE copolymer, VdF / TFE / PAVE copolymer, VdF / HFP / PAVE copolymer, VdF / HFP / TFE / PAVE copolymer, VdF / TFE / propylene (Pr) copolymer, VdF / ethylene (Et) / HFP copolymer and VdF / At least one copolymer selected from the group consisting of copolymers of fluorine-containing monomers represented by the formula (2) is preferred, and as other comonomer other than VdF, TFE, It is more preferable to have at least one comonomer selected from the group consisting of HFP and PAVE. Among these, VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / copolymer of fluorine-containing monomer represented by formula (2), VdF / PAVE copolymer, VdF / TFE / PAVE copolymer, VdF / HFP / PAVE copolymer, and at least one copolymer selected from the group consisting of VdF / HFP / TFE / PAVE copolymer is preferable, VdF / HFP copolymer, VdF / HFP / TFE copolymer, VdF / copolymer of fluorine-containing monomer represented by formula (2) and at least one copolymer selected from the group consisting of VdF / PAVE copolymer Preferably, at least one copolymer selected from the group consisting of VdF / HFP copolymer, VdF / copolymer of fluorine-containing monomer represented by formula (2), and VdF / PAVE copolymer Particularly preferred.

  The VdF / HFP copolymer preferably has a VdF / HFP composition of (45 to 85) / (55 to 15) (mol%), more preferably (50 to 80) / (50 to 20). (Mol%), more preferably (60-80) / (40-20) (mol%).

  The VdF / TFE / HFP copolymer preferably has a VdF / TFE / HFP composition of (30-80) / (4-35) / (10-35) (mol%).

  As the VdF / PAVE copolymer, a VdF / PAVE composition having a composition of (65 to 90) / (35 to 10) (mol%) is preferable.

  As the VdF / TFE / PAVE copolymer, a VdF / TFE / PAVE composition having a composition of (40-80) / (3-40) / (15-35) (mol%) is preferable.

  As the VdF / HFP / PAVE copolymer, a VdF / HFP / PAVE composition having a composition of (65 to 90) / (3 to 25) / (3 to 25) (mol%) is preferable.

  As VdF / HFP / TFE / PAVE copolymerization, the composition of VdF / HFP / TFE / PAVE is (40-90) / (0-25) / (0-40) / (3-35) (mol%). The thing of (40-80) / (3-25) / (3-40) / (3-25) (mol%) is more preferable.

  As the fluorine-containing monomer (2) -based copolymer represented by VdF / formula (2), the molar ratio of VdF / fluorine-containing monomer (2) unit is 85/15 to 20/80. , VdF and other monomer units other than fluorine-containing monomer (2) are preferably 0 to 50 mol% of all monomer units, and VdF / mol% of fluorine-containing monomer (2) unit. The ratio is more preferably 80/20 to 20/80. The molar ratio of VdF / fluorinated monomer (2) unit is 85/15 to 50/50, and other monomer units other than VdF and fluorine-containing monomer (2) are all monomer units. Those having a content of 1 to 50 mol% are also preferred. As monomers other than VdF and fluorine-containing monomer (2), TFE, HFP, PMVE, perfluoroethyl vinyl ether (PEVE), PPVE, CTFE, trifluoroethylene, hexafluoroisobutene, vinyl fluoride, Monomers exemplified as the above-mentioned VdF comonomer such as ethylene (Et), propylene (Pr), alkyl vinyl ether, a monomer giving a crosslinkable group, and a reactive emulsifier are preferable, and among them, PMVE, CTFE, More preferably, they are HFP and TFE.

  The TFE / propylene (Pr) -based fluororubber is a fluorine-containing copolymer composed of TFE 45 to 70 mol% and propylene (Pr) 55 to 30 mol%. In addition to these two components, 0 to 40 mol% of a specific third component (for example, PAVE) may be contained.

  As an ethylene (Et) / HFP copolymer, it is preferable that the composition of Et / HFP is (35-80) / (65-20) (mol%), (40-75) / (60-25) ) (Mol%) is more preferable.

  In the Et / HFP / TFE copolymer, the composition of Et / HFP / TFE is preferably (35 to 75) / (25 to 50) / (0 to 15) (mol%), and (45 to 75). ) / (25-45) / (0-10) (mol%) is more preferred.

  Examples of the perfluoro fluorine rubber include those made of TFE / PAVE. The composition of TFE / PAVE is preferably (50 to 90) / (50 to 10) (mol%), more preferably (50 to 80) / (50 to 20) (mol%), More preferably, it is (55-75) / (45-25) (mol%).

  Examples of PAVE in this case include PMVE, PPVE, and the like, and these can be used alone or in any combination.

  The fluororubber (A) preferably has a number average molecular weight Mn of 5,000 to 500,000, more preferably 10,000 to 500,000, particularly preferably 20,000 to 500,000.

  For example, when it is desired to lower the viscosity of the fluororubber composition, the above fluororubber (A) may be blended with another fluororubber. Examples of other fluororubber include low molecular weight liquid fluororubber (number average molecular weight of 1000 or more), low molecular weight fluororubber having a number average molecular weight of about 10,000, and fluororubber having a number average molecular weight of about 100,000 to 200,000.

  From the viewpoint of processability, the fluororubber (A) preferably has a Mooney viscosity at 100 ° C. of 20 to 200, more preferably 30 to 180. Mooney viscosity is measured according to ASTM-D1646 and JIS K6300.

  The non-perfluorofluororubber and perfluorofluororubber described above can be produced by conventional methods such as emulsion polymerization, suspension polymerization, and solution polymerization. In particular, according to a polymerization method using an iodine (bromine) compound known as iodine (bromine) transfer polymerization, a fluororubber having a narrow molecular weight distribution can be produced.

  What is exemplified as the non-perfluorofluororubber or perfluorofluororubber is a constitution of a main monomer, and a copolymer obtained by copolymerizing a monomer giving a crosslinkable group can also be suitably used. As the monomer that gives a crosslinkable group, any monomer that can introduce an appropriate crosslinkable group depending on the production method and the crosslinking system may be used. For example, an iodine atom, a bromine atom, a carbon-carbon double bond, a cyano group, Examples include known polymerizable compounds containing a carboxyl group, a hydroxyl group, an amino group, an ester group, and a chain transfer agent.

であり、ｎは０〜５の整数）
ＣＦ₂＝ＣＦＣＦ₂（ＯＣＦ（ＣＦ₃）ＣＦ₂）_m
（ＯＣＨ₂ＣＦ₂ＣＦ₂）_nＯＣＨ₂ＣＦ₂−Ｘ¹ （７）
（式中、ｍは０〜５の整数、ｎは０〜５の整数）
ＣＦ₂＝ＣＦＣＦ₂（ＯＣＨ₂ＣＦ₂ＣＦ₂）_m
（ＯＣＦ（ＣＦ₃）ＣＦ₂）_nＯＣＦ（ＣＦ₃）−Ｘ¹ （８）
（式中、ｍは０〜５の整数、ｎは０〜５の整数）
ＣＦ₂＝ＣＦ（ＯＣＦ₂ＣＦ（ＣＦ₃））_mＯ（ＣＦ₂）_n−Ｘ¹ （９）
（式中、ｍは０〜５の整数、ｎは１〜８の整数）
ＣＦ₂＝ＣＦ（ＯＣＦ₂ＣＦ（ＣＦ₃））_m−Ｘ¹ （１０）
（式中、ｍは１〜５の整数）
ＣＦ₂＝ＣＦＯＣＦ₂（ＣＦ（ＣＦ₃）ＯＣＦ₂）_nＣＦ（−Ｘ¹）ＣＦ₃ （１１）
（式中、ｎは１〜４の整数）
ＣＦ₂＝ＣＦＯ（ＣＦ₂）_nＯＣＦ（ＣＦ₃）−Ｘ¹ （１２）
（式中、ｎは２〜５の整数）
ＣＦ₂＝ＣＦＯ（ＣＦ₂）_n−（Ｃ₆Ｈ₄）−Ｘ¹ （１３）
（式中、ｎは１〜６の整数）
ＣＦ₂＝ＣＦ（ＯＣＦ₂ＣＦ（ＣＦ₃））_nＯＣＦ₂ＣＦ（ＣＦ₃）−Ｘ¹ （１４）
（式中、ｎは１〜２の整数）
ＣＨ₂＝ＣＦＣＦ₂Ｏ（ＣＦ（ＣＦ₃）ＣＦ₂Ｏ）_nＣＦ（ＣＦ₃）−Ｘ¹ （１５）
（式中、ｎは０〜５の整数）、
ＣＦ₂＝ＣＦＯ（ＣＦ₂ＣＦ（ＣＦ₃）Ｏ）_m（ＣＦ₂）_n−Ｘ¹ （１６）
（式中、ｍは０〜５の整数、ｎは１〜３の整数）
ＣＨ₂＝ＣＦＣＦ₂ＯＣＦ（ＣＦ₃）ＯＣＦ（ＣＦ₃）−Ｘ¹ （１７）
ＣＨ₂＝ＣＦＣＦ₂ＯＣＨ₂ＣＦ₂−Ｘ¹ （１８）
ＣＦ₂＝ＣＦＯ（ＣＦ₂ＣＦ（ＣＦ₃）Ｏ）_mＣＦ₂ＣＦ（ＣＦ₃）−Ｘ¹ （１９）
（式中、ｍは０以上の整数）
ＣＦ₂＝ＣＦＯＣＦ（ＣＦ₃）ＣＦ₂Ｏ（ＣＦ₂）_n−Ｘ¹ （２０）
（式中、ｎは１以上の整数）
ＣＦ₂＝ＣＦＯＣＦ₂ＯＣＦ₂ＣＦ（ＣＦ₃）ＯＣＦ₂−Ｘ¹ （２１）
ＣＨ₂＝ＣＨ−（ＣＦ₂）_nＸ¹ （２２）
（式中、ｎは２〜８の整数）
（一般式（５）〜（２２）中、Ｘ¹は前記と同様）
で表されるヨウ素含有モノマー、臭素含有モノマーなどが挙げられ、これらをそれぞれ単独で、または任意に組合わせて用いることができる。As a monomer that gives a preferred crosslinkable group,
General formula (3):
CY ¹ ₂ = CY ² R _f ² X ¹ (3)
(Wherein Y ¹ and Y ² are a fluorine atom, a hydrogen atom, or —CH ₃ ; R _f ² may have one or more ether-bonded oxygen atoms, and may have an aromatic ring. , A linear or branched fluorine-containing alkylene group in which part or all of the hydrogen atoms are substituted with fluorine atoms; X ¹ is an iodine atom or a bromine atom)
The compound shown by these is mentioned. Specifically, for example, the general formula (4):
CY ¹ ₂ = CY ² R _f ³ CHR ¹ -X ¹ (4)
(In the formula, Y ¹ , Y ² and X ¹ are the same as described above, and R _f ³ may have one or more ether-bonded oxygen atoms, and part or all of the hydrogen atoms are substituted with fluorine atoms. Linear or branched fluorine-containing alkylene group, that is, a linear or branched fluorine-containing alkylene group in which some or all of the hydrogen atoms are substituted with fluorine atoms, and part or all of the hydrogen atoms are fluorine a linear or branched fluorine-containing oxyalkylene group substituted with atoms or a fluorine-containing polyoxyalkylene group partially or entirely a linear or branched substituted with fluorine atoms of the hydrogen atom,; R ¹ is Hydrogen atom or methyl group)
Iodine-containing monomer, bromine-containing monomer represented by general formulas (5) to (22):
CY ⁴ ₂ = CY ⁴ (CF ₂ ) _n −X ¹ (5)
Wherein Y ⁴ is the same or different and is a hydrogen atom or a fluorine atom, and n is an integer of 1 to 8.
^{_{CF 2 = CFCF 2 R f 4}} -X 1 (6)
(Where

And n is an integer from 0 to 5)
CF ₂ = CFCF ₂ (OCF (CF ₃ ) CF ₂ ) _{m
(OCH 2 CF 2 CF 2)} n OCH 2 CF 2 -X 1 (7)
(In the formula, m is an integer of 0 to 5, n is an integer of 0 to 5)
CF ₂ = CFCF ₂ (OCH ₂ CF ₂ CF ₂ ) _m
(OCF (CF ₃ ) CF ₂ ) _n OCF (CF ₃ ) -X ¹ (8)
(In the formula, m is an integer of 0 to 5, n is an integer of 0 to 5)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m O (CF 2) n -X 1 (9)
(Wherein, m is an integer from 0 to 5, and n is an integer from 1 to 8)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m -X 1 (10)
(Where m is an integer from 1 to 5)
_{CF 2 = CFOCF 2 (CF (} CF 3) OCF 2) n CF (-X 1) CF 3 (11)
(Where n is an integer from 1 to 4)
_{CF 2 = CFO (CF 2)} n OCF (CF 3) -X 1 (12)
(Where n is an integer from 2 to 5)
_{CF 2 = CFO (CF 2)} n - (C 6 H 4) -X 1 (13)
(Where n is an integer from 1 to 6)
_{CF 2 = CF (OCF 2 CF} (CF 3)) n OCF 2 CF (CF 3) -X 1 (14)
(Where n is an integer from 1 to 2)
_{CH 2 = CFCF 2 O (CF} (CF 3) CF 2 O) n CF (CF 3) -X 1 (15)
(Where n is an integer from 0 to 5),
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m (CF 2) n -X 1 (16)
(In the formula, m is an integer of 0 to 5, n is an integer of 1 to 3)
_{CH 2 = CFCF 2 OCF (CF} 3) OCF (CF 3) -X 1 (17)
_{CH 2 = CFCF 2 OCH 2 CF} 2 -X 1 (18)
_{CF 2 = CFO (CF 2 CF} (CF 3) O) m CF 2 CF (CF 3) -X 1 (19)
(Where m is an integer of 0 or more)
_{CF 2 = CFOCF (CF 3)} CF 2 O (CF 2) n -X 1 (20)
(Where n is an integer of 1 or more)
_{CF 2 = CFOCF 2 OCF 2 CF} (CF 3) OCF 2 -X 1 (21)
_{CH 2 = CH- (CF 2)} n X 1 (22)
(Where n is an integer from 2 to 8)
(In the general formulas (5) to (22), X ¹ is the same as above)
The iodine-containing monomer represented by these, the bromine-containing monomer, etc. are mentioned, These can be used individually or in arbitrary combinations, respectively.

（式中、ｍは１〜５の整数であり、ｎは０〜３の整数）
で表されるヨウ素含有フッ素化ビニルエーテルが好ましく挙げられ、より具体的には、

などが挙げられるが、これらの中でも、ＩＣＨ₂ＣＦ₂ＣＦ₂ＯＣＦ＝ＣＦ₂が好ましい。As the iodine-containing monomer or bromine-containing monomer represented by the general formula (4), the general formula (23):

(In the formula, m is an integer of 1 to 5, and n is an integer of 0 to 3).
Preferred examples include iodine-containing fluorinated vinyl ethers represented by:

Among them, ICH ₂ CF ₂ CF ₂ OCF═CF ₂ is preferable among these.

More specifically, preferred examples of the iodine-containing monomer or bromine-containing monomer represented by the general formula (5) include ICF ₂ CF ₂ CF═CH ₂ and I (CF ₂ CF ₂ ) ₂ CF═CH ₂ .

More specifically, the iodine-containing monomer or bromine-containing monomer represented by the general formula (9) is preferably I (CF ₂ CF ₂ ) ₂ OCF═CF ₂ .

More specifically, preferred examples of the iodine-containing monomer or bromine-containing monomer represented by the general formula (22) include CH ₂ ═CHCF ₂ CF ₂ I and I (CF ₂ CF ₂ ) ₂ CH═CH ₂ .

Further, the ^{formula: R 2 R 3 C = CR} 4 -Z-CR 5 = CR 6 R 7
(Wherein R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different, all are H, or an alkyl group having 1 to 5 carbon atoms; Z is a linear or branched group; A bisolefin compound which may contain an oxygen atom, and preferably is an at least partially fluorinated alkylene or cycloalkylene group having 1 to 18 carbon atoms, or (per) fluoropolyoxyalkylene group). Preferred as a monomer for providing a functional group. In the present specification, “(per) fluoropolyoxyalkylene group” means “fluoropolyoxyalkylene group or perfluoropolyoxyalkylene group”.

Z is preferably a (per) fluoroalkylene group having 4 to 12 carbon atoms, and R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are preferably hydrogen atoms.

When Z is a (per) fluoropolyoxyalkylene group, the formula:
_{- (Q) p -CF 2 O-} (CF 2 CF 2 O) m - (CF 2 O) n -CF 2 - (Q) p -
(In the formula, Q is an alkylene group having 1 to 10 carbon atoms or an oxyalkylene group having 2 to 10 carbon atoms, p is 0 or 1, and m and n have an m / n ratio of 0.2 to 5. And the (per) fluoropolyoxyalkylene group is an integer such that the molecular weight of the (per) fluoropolyoxyalkylene group is in the range of 500 to 10,000, preferably 1000 to 4000. . In this formula, Q is preferably selected from —CH ₂ OCH ₂ — and —CH ₂ O (CH ₂ CH ₂ O) _s CH ₂ — (s = 1 to 3).

Preferred bisolefins are
_{CH 2 = CH- (CF 2)} 4 -CH = CH 2,
_{CH 2 = CH- (CF 2)} 6 -CH = CH 2,
^{_{Formula: CH 2 = CH-Z 1}} -CH = CH 2
(In the formula, Z ¹ represents —CH ₂ OCH ₂ —CF ₂ O— (CF ₂ CF ₂ O) _m — (CF ₂ O) _n —CF ₂ —CH ₂ OCH ₂ — (m / n is 0.5)). )
Etc.

Among _{them, CH 2 = CH- (CF 2} ) 6 represented by -CH = CH ₂ 3,3,4,4,5,5,6,6,7,7,8,8- dodecafluoro -1, 9-decadiene is preferred.

(B) Carbon Black In the fluororubber composition of the present invention, the carbon black (B) comprises a fluororubber (A), an organic amine compound (C1) and / or an acid acceptor (C2), and a crosslinking agent (D). And, it is not limited as long as it gives a cross-linked fluororubber which is excellent not only in heat resistance but also in mechanical properties at high temperature by crosslinking in a form in which a crosslinking accelerator (E) is blended.

Examples of such carbon black include furnace black, acetylene black, thermal black, channel black, graphite and the like. Specifically, for example, SAF-HS (N ₂ SA: 142 m ² / g, DBP: 130 ml / 100 g), SAF (N ₂ SA: 142 m ² / g, DBP: 115 ml / 100 g), N234 (N ₂ SA: 126 m ² / g, DBP: 125 ml / 100 g), ISAF (N ₂ SA: 119 m ² / g, DBP: 114 ml) / 100 g), ISAF-LS (N ₂ SA: 106 m ² / g, DBP: 75 ml / 100 g), ISAF-HS (N ₂ SA: 99 m ² / g, DBP: 129 ml / 100 g), N339 (N ₂ SA: 93 m ² / g, DBP: 119 ml / 100 g), HA F-LS (N ₂ SA: 84 m ² / g, DBP: 75 ml / 100 g), HAS-HS (N ₂ SA: 82 m ² / g, DBP: 126 ml / 100 g), HAF (N ₂ SA: 79 m ² / g DBP: 101 ml / 100 g), N351 (N ₂ SA: 74 m ² / g, DBP: 127 ml / 100 g), LI-HAF (N ₂ SA: 74 m ² / g, DBP: 101 ml / 100 g), MAF-HS ( N ₂ SA: 56 m ² / g, DBP: 158 ml / 100 g), MAF (N ₂ SA: 49 m ² / g, DBP: 133 ml / 100 g), FEF-HS (N ₂ SA: 42 m ² / g, DBP: 160 ml) / 100 g), FEF (N ₂ SA: 42 m ² / g, DBP: 115 ml / 100 g), SRF-HS (N ₂ SA: 32 m ² / g, DBP: 140 ml / 100 g), SRF-HS (N ₂ SA: 29 m ² / g, DBP: 152 ml / 100 g), GPF (N ₂ SA: 27 m ² / g, DBP: 87 ml / 100 g), SRF (N ₂ SA : 27 m ² / g, DBP: 68 ml / 100 g), SRF-LS (N ₂ SA: 23 m ² / g, DBP: 51 ml / 100 g), FT (N ₂ SA: 19 m ² / g, DBP: 42 ml / 100 g) , MT (N ₂ SA: 8 m ² / g, DBP: 43 ml / 100 g), and the like. These carbon blacks may be used alone or in combination of two or more.

Among these, carbon black preferably has a nitrogen adsorption specific surface area (N ₂ SA) of 5 to 180 m ² / g and a dibutyl phthalate (DBP) oil absorption of 40 to 180 ml / 100 g. It is done. When carbon black having a high value of N ₂ SA or DBP is used, the loss elastic modulus E ″ and the storage elastic modulus E ′ described later are high.

When the nitrogen adsorption specific surface area (N ₂ SA) is smaller than 5 m ² / g, mechanical properties when blended with rubber tend to be reduced. From this viewpoint, the nitrogen adsorption specific surface area (N ₂ SA) is 10 m ^2. / G or more is preferable, 20 m ² / g or more is more preferable, and 25 m ² / g or more is particularly preferable. The upper limit is preferably 180 m ² / g from the viewpoint of easy availability.

  When the dibutyl phthalate (DBP) oil absorption is less than 40 ml / 100 g, the mechanical properties when blended with rubber tend to decrease. From this viewpoint, 50 ml / 100 g or more, further 60 ml / 100 g or more, particularly 80 ml. / 100g or more is preferable. From the viewpoint of easy availability, the upper limit is preferably 175 ml / 100 g, more preferably 170 ml / 100 g.

  As for the compounding quantity of carbon black (B), 5-50 mass parts is preferable with respect to 100 mass parts of fluororubbers (A). If the carbon black (B) is too much, the mechanical properties tend to decrease, and if it is too small, the mechanical properties tend to decrease. A more preferable blending amount is preferably 6 parts by mass or more, more preferably 10 parts by mass or more with respect to 100 parts by mass of the fluororubber (A), from the viewpoint of good physical property balance, and 49 parts by mass from the point of good physical property balance. The following is preferable, and 45 parts by mass or less is more preferable.

(C1) Organic amine compound In the presence of the organic amine compound (C1), the fluororubber (A) and the carbon black (B) are set to a maximum temperature Tm of 80 ° C. to 220 ° C. at the time of kneading and discharged at that temperature. That is, the maximum temperature Tm of the kneaded product at the time of kneading and the maximum temperature of the kneaded product at the time of discharging, respectively. By setting the temperature to 80 ° C. to 220 ° C., an excellent effect can be obtained in terms of improving mechanical properties at high temperatures and improving fatigue properties at high temperatures (for example, fatigue resistance in repeated use). When kneading fluororubber with a crosslinking agent or the like, it is known that an alkylamine compound is simply blended as a processing aid. However, kneading an organic amine compound in the above-mentioned temperature range is a conventional alkyl compound. It is not planned for the purpose of compounding amine compounds.

  When kneading the organic amine compound (C1), if the maximum temperature Tm is lower than 80 ° C., the reinforcing property is lowered, which is not preferable. The lower limit of the preferable temperature Tm is 90 ° C, more preferably 95 ° C, and particularly preferably 100 ° C. The upper limit is 220 ° C. If this temperature is exceeded, the organic amine compound volatilizes, which is not preferable. A preferable upper limit temperature Tm is 215 ° C, more preferably 210 ° C, and particularly preferably 200 ° C.

The organic amine compound (C1) used in the present invention includes a primary amine represented by R ¹ NH ₂ , a secondary amine represented by R ¹ R ² NH, and a tertiary amine represented by R ¹ R ² R ³ N. Preferably mentioned. R ¹ , R ² and R ³ are the same or different, and all are preferably an alkyl group having 1 to 50 carbon atoms, and the alkyl group may contain a benzene ring as a functional group, a double bond, a conjugated double Bonds may be included. The alkyl group may be linear or branched.

  Examples of primary amines include coconut amine, octylamine, laurylamine, stearylamine, oleylamine, beef tallow amine, 17-phenyl-heptadecylamine, octadec-7,11-dienylamine, octadec-7,9-dienylamine, octadec- 9-enylamine, 7-methyl-octadec-7-enylamine and the like. Examples of the secondary amine include distearylamine, and examples of the tertiary amine include dimethyloctylamine, dimethyldecylamine, dimethyllaurylamine, Examples include dimethyl myristyl amine, dimethyl palmityl amine, dimethyl stearyl amine, and dimethyl behenyl amine. Of these, amines having about 20 carbon atoms, particularly primary amines, are preferred from the standpoint of easy availability and reinforcement.

  0.01-10 mass parts is preferable with respect to 100 mass parts of fluororubbers (A), and, as for the compounding quantity of an organic amine compound (C1), 0.01-5 mass parts is still more preferable. When the amount of the organic amine compound (C1) is too large, kneading tends to be difficult, and when the amount is too small, the reinforcing property tends to be lowered. A more preferable blending amount is 0.1 parts by mass or more with respect to 100 parts by mass of the fluororubber (A) from the viewpoint of reinforcement, and 4 parts by mass or less from the viewpoint of reinforcement and ease of kneading. .

(C2) Acid acceptor In the presence of the acid acceptor (C2), the fluororubber (A) and the carbon black (B) are preliminarily set to a maximum temperature Tm of 80 ° C. to 220 ° C. during the kneading, and discharged at that temperature. That is, the maximum temperature Tm of the kneaded product at the time of kneading and the maximum temperature of the kneaded product at the time of discharging, respectively. By setting the temperature to 80 ° C. to 220 ° C., an excellent effect can be obtained in terms of improving mechanical properties at high temperatures and improving fatigue properties at high temperatures (for example, fatigue resistance in repeated use). It is known that calcium hydroxide, magnesium oxide, hydrotalcite and the like coexist as an acid acceptor during crosslinking. However, kneading an acid acceptor in the temperature range as described above is a conventional acid acceptor. It is not planned for the purpose of formulating the agent.

  When kneading the acid acceptor (C2), if the maximum temperature Tm is lower than 80 ° C., the reinforcing property is lowered, which is not preferable. The lower limit of the preferable temperature Tm is 90 ° C, more preferably 95 ° C, and particularly preferably 100 ° C. The upper limit is 220 ° C., and if this temperature is exceeded, it is not preferable from the viewpoint of deterioration of physical properties. A preferable upper limit temperature Tm is 215 ° C, more preferably 210 ° C, and particularly preferably 200 ° C.

  Examples of the acid-accepting agent (C2) used in the present invention include calcium oxide, magnesium oxide, lead oxide, zinc oxide, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, hydrotalcite and the like. You may mix | blend a seed | species or more suitably. As the acid acceptor (C2), metal hydroxides such as calcium hydroxide; metal oxides such as magnesium oxide and zinc oxide, hydrotalcite and the like are preferable, and zinc oxide is particularly preferable.

  As for the compounding quantity of an acid acceptor (C2), 0.01-10 mass parts is preferable with respect to 100 mass parts of fluororubbers (A). If the acid acceptor (C2) is too much, kneading tends to be difficult, and if it is too little, the reinforcing property tends to be lowered. A more preferable blending amount is 0.1 parts by mass or more with respect to 100 parts by mass of the fluororubber (A) from the viewpoint of reinforcement, and is preferably 8 parts by mass or less from the viewpoint of physical properties and ease of kneading. 5 parts by mass or less is more preferable.

  In the present invention, when the organic amine compound (C1) and / or the acid acceptor (C2) are kneaded with the fluororubber (A) and the carbon black (B) at a maximum temperature Tm of 80 ° C. to 220 ° C., the fluororubber (A ) And carbon black (B) are once kneaded and then added and kneaded, but fluororubber (A) and carbon black (B) are added in the presence of organic amine compound (C1) and / or acid acceptor (C2). It is preferable that the organic amine compound (C1) and / or the acid acceptor (C2), the fluororubber (A), and the carbon black (B) are kneaded in one step. As a result, a more excellent effect can be expected in terms of improvement in mechanical properties at high temperatures in the cross-linked product of the obtained rubber composition and improvement in fatigue properties at high temperatures (for example, fatigue resistance in repeated use).

  Among the organic amine compound (C1) and / or the acid acceptor (C2), the organic amine compound (C1) is preferable from the viewpoint of fatigue characteristics at high temperatures (for example, fatigue resistance in repeated use). Particularly preferred.

  In the method for producing the fluororubber composition of the present invention, the fluororubber (A) and the carbon black (B) are kneaded at the time of kneading in the presence of the organic amine compound (C1) and / or the acid acceptor (C2). The maximum temperature Tm is 80 ° C. to 220 ° C., and it is only necessary to be kneaded under the conditions of discharging at that temperature, that is, the fluororubber (A) and the carbon black (B) are kneaded, and the kneaded material at the time of kneading The maximum temperature Tm and the maximum temperature of the kneaded product at the time of discharging may be 80 ° C. to 220 ° C., respectively, and the order of kneading of other components and the number of kneading are not particularly limited. Can be prepared.

  More specifically, the following methods may be mentioned, but the present invention is not limited to these methods.

(1) A predetermined amount of fluororubber (A), carbon black (B), organic amine compound (C1) and / or acid acceptor (C2) is charged into a closed kneader, and the average shear rate of the rotor is 50 to 1000. (1 / second), preferably 100 to 1000 (1 / second), more preferably 200 to 1000 (1 / second), and kneading under conditions where the maximum temperature Tm is 80 to 220 ° C. Examples of the closed kneader include a pressure kneader, a Banbury mixer, a uniaxial kneader, and a biaxial kneader.

(2) A predetermined amount of fluororubber (A), carbon black (B), organic amine compound (C1) and / or acid acceptor (C2) is put into a roll kneader, and the average shear rate of the rotor is 50 (1 / Second), the method of kneading under the condition that the maximum temperature Tm is 80 to 220 ° C.

  The fluororubber composition obtained by the above methods (1) and (2) does not contain a crosslinking agent (and / or a crosslinking aid) or a crosslinking accelerator. Moreover, you may perform kneading | mixing of the method of said (1) and (2) in multiple times. When performing a plurality of times, the second and subsequent kneading conditions may be the same as the methods (1) and (2) except that the maximum temperature Tm is 140 ° C. or lower.

  One of the methods for preparing the fluororubber composition into a crosslinkable fluororubber composition is, for example, obtained by the above methods (1) and (2), or the above methods (1) and (2). This is a method in which a cross-linking agent (D) (and / or a cross-linking aid (F)) and a cross-linking accelerator (E) are further blended and kneaded with the fluororubber composition obtained by repeating a plurality of times.

  The crosslinking agent (D) (and / or the crosslinking assistant (F)) and the crosslinking accelerator (E) may be blended and kneaded at the same time. First, the crosslinking accelerator (E) is blended and kneaded. D) (and / or crosslinking aid (F)) may be blended and kneaded. The kneading conditions of the crosslinking agent (D) (and / or the crosslinking assistant (F)) and the crosslinking accelerator (E) are the methods of the above (1) and (2) except that the maximum temperature Tm is 130 ° C. or less. The same conditions are acceptable.

  Another method for preparing the crosslinkable fluororubber composition is, for example, a roll kneader with fluororubber (A), carbon black (B), organic amine compound (C1) and / or acid acceptor (C2), and crosslinker. (D) (and / or crosslinking aid (F)) and crosslinking accelerator (E) are charged in a predetermined amount in an appropriate order, and the average shear rate of the rotor is kneaded under a condition of 50 (1 / second) or more, The method which makes maximum temperature Tm 80-130 degreeC is mentioned.

  In the case of a polyol crosslinking system, a uniform dispersion may be used by previously mixing the fluororubber (A), the crosslinking agent (D), and the crosslinking accelerator (E). For example, the fluororubber (A), the polyol-based crosslinking agent and the crosslinking accelerator are first kneaded, then the carbon black (B) and the organic amine compound (C1) are blended and kneaded, and the maximum temperature Tm is 80 to 220 ° C. To do. Finally, there is a method in which an acid acceptor is blended and kneaded to obtain a maximum temperature Tm of 130 ° C. or lower. In kneading, it is more preferable to employ a method of kneading at an average shear rate of 50 (1 / second) or more.

  A preferred rubber composition of the present invention has a shear elastic modulus G ′ (1) when dynamic strain is 1% when uncrosslinked in a dynamic viscoelasticity test (measurement frequency: 1 Hz, measurement temperature: 100 ° C.) using a rubber process analyzer. %) And the difference δG ′ (G ′ (1%) − G ′ (100%)) of the shear elastic modulus G ′ (100%) at a dynamic strain of 100% is 120 kPa or more and 3,000 kPa or less. In addition, when performing the above-mentioned pre-kneading (kneading of said (1), (2) etc.), it is more preferable that the obtained pre-kneaded material has the said difference (delta) G '.

  The difference δG ′ is used as an index for evaluating the reinforcing property of the rubber composition, and is measured and calculated by a dynamic viscoelasticity test using a rubber process analyzer.

  A fluororubber composition having a difference δG ′ in the range of 120 kPa to 3,000 kPa is advantageous in terms of normal properties, mechanical properties at high temperatures, fatigue properties at high temperatures, and the like.

  The difference δG ′ is preferably 150 kPa or more, more preferably 160 kPa or more, from the viewpoint of good normal physical properties, mechanical properties at high temperatures, fatigue properties at high temperatures, and the like, and normal physical properties, mechanical properties at high temperatures, and high temperatures. From the viewpoint of good fatigue characteristics, it is preferably 2800 kPa or less, more preferably 2500 kPa or less.

  In addition, by forming a good carbon gel network reinforcing structure, a fluororubber composition having a specific difference δG ′ described later, and a crosslinked product having specific loss elastic modulus E ″ and storage elastic modulus E ′ described later are obtained. From this point of view, it is desirable to perform kneading at an average shear rate of 50 (1 / second) or more.

The average shear rate (1 / second) is calculated by the following formula.
Average shear rate (1 / second) = (π × D × R) / (60 (second) × c)
(Where
D: Rotor diameter or roll diameter (cm)
R: Rotational speed (rpm)
c: Chip clearance (cm. Distance between rotor and casing, or distance between rolls)

  Examples of the crosslinking agent (D) and crosslinking accelerator (E) constituting the crosslinkable rubber composition include the following.

(D) Cross-linking agent The cross-linking agent (D) is a cross-linking system, the type of fluororubber (A) to be cross-linked (for example, copolymer composition, presence / absence or type of cross-linkable group), and specific uses and uses of the resulting cross-linked product It can be appropriately selected according to the form and other kneading conditions.

  As the crosslinking system, for example, a peroxide crosslinking system, a polyol crosslinking system, a polyamine crosslinking system, an oxazole crosslinking system, a thiazole crosslinking system, an imidazole crosslinking system, a triazine crosslinking system, and the like can be employed.

(Peroxide crosslinking system)
When cross-linking with a peroxide cross-linking system, it has a carbon-carbon bond at the cross-linking point. Compared with it, it is characterized by excellent chemical resistance and steam resistance.

  The peroxide cross-linking agent may be a peroxide that can easily generate a peroxy radical in the presence of heat or a redox system. Specifically, for example, 1,1-bis (t -Butylperoxy) -3,5,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α-bis (t-butylperoxy) -p-diisopropylbenzene, α, α-bis (t-butylperoxy) -m-diisopropylbenzene, 2,5-dimethyl-2,5-di (t- Butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne-3, benzoyl peroxide, t-butylperoxybenze , T- butyl peroxybenzoate, t- butyl peroxy maleic acid, and organic peroxides such as t-butyl peroxy isopropyl carbonate. Among these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane or 2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne-3 is preferable.

  In addition, in the peroxide crosslinking system, it is usually preferable to include a crosslinking accelerator (E1). Examples of crosslinking accelerators for peroxide crosslinking agents, particularly organic peroxide crosslinking agents include triallyl cyanurate, triallyl isocyanurate (TAIC), triacryl formal, triallyl trimellitate, maleimide, N -Phenylenemaleimide, N, N'-m-phenylenebismaleimide, p-quinonedioxime, p, p'-dibenzoylquinonedioxime, dipropargyl terephthalate, diallyl phthalate, tetraallyl terephthalate amide, triallyl phosphate, bismaleimide Fluorinated triallyl isocyanurate (1,3,5-tris (2,3,3-trifluoro-2-propenyl) -1,3,5-triazine-2,4,6-trione), tris (diallylamine) ) -S-triazine, triallyl phosphite, N, Diallylacrylamide, 1,6-divinyldodecafluorohexane, hexaallylphosphoramide, N, N, N ′, N′-tetraallylphthalamide, N, N, N ′, N′-tetraallylmalonamide, tri Vinyl isocyanurate, 2,4,6-trivinylmethyltrisiloxane, tri (5-norbornene-2-methylene) cyanurate, triallyl phosphite, trimethallyl isocyanurate (TMAIC), 3,3,4,4,5 5,6,6,7,7,8,8-dodecafluoro-1,9-decadiene and the like. Among these, from the viewpoint of crosslinkability and physical properties of the crosslinked product, triallyl isocyanurate (TAIC), trimethallyl isocyanurate (TMAIC), 3,3,4,4,5,5,6,6,7,7 , 8,8-dodecafluoro-1,9-decadiene, maleimide, N, N′-m-phenylenebismaleimide, p-quinonedioxime, p, p′-dibenzoylquinonedioxime are preferred.

  As the fluoro rubber (A) suitable for the peroxide crosslinking system, any of a perfluoro fluoro rubber and a non-perfluoro fluoro rubber containing at least a TFE unit, a VdF unit, or a fluoromonomer unit of the formula (1) is used. In particular, at least one rubber selected from the group consisting of VdF rubber and TFE / Pr rubber is preferable.

  Further, from the viewpoint of crosslinkability, the fluororubber (A) suitable for the peroxide crosslinking system is preferably a fluororubber containing iodine atoms and / or bromine atoms as crosslinking points. The content of iodine atom and / or bromine atom is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, and particularly preferably 0.01 to 3% by mass.

  As a compounding quantity of a peroxide crosslinking agent, it is preferable that it is 0.01-10 mass parts with respect to 100 mass parts of fluororubber (A), More preferably, it is 0.1-9 mass parts. When the peroxide crosslinking agent is less than 0.01 parts by mass, the crosslinking of the fluororubber (A) tends not to proceed sufficiently, and when it exceeds 10 parts by mass, the balance of physical properties tends to decrease.

  Moreover, the compounding quantity of a crosslinking accelerator (E1) is 0.01-10 mass parts with respect to 100 mass parts of fluororubber (A), Preferably it is 0.1-5 mass parts. When the amount of the crosslinking accelerator is less than 0.01 parts by mass, the crosslinking time tends to be unpractical, and when the amount exceeds 10 parts by mass, the crosslinking time becomes too fast and the physical property balance is lowered. Tend. A preferable upper limit of the crosslinking accelerator (E1) is 9 parts by mass, further 8 parts by mass, or less than 8 parts by mass, particularly 7 parts by mass.

(Polyol crosslinking system)
Crosslinking by a polyol crosslinking system is preferable in that it has a carbon-oxygen bond at the crosslinking point, has a small compression set, and is excellent in moldability.

  As the polyol crosslinking agent, a compound conventionally known as a crosslinking agent for fluororubber can be used. For example, a polyhydroxy compound, particularly a polyhydroxy aromatic compound is preferably used from the viewpoint of excellent heat resistance.

  The polyhydroxy aromatic compound is not particularly limited. For example, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A), 2,2-bis (4-hydroxyphenyl) perfluoropropane. (Hereinafter referred to as bisphenol AF), resorcin, 1,3-dihydroxybenzene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 4,4′-dihydroxydiphenyl, 4,4 ′ -Dihydroxystilbene, 2,6-dihydroxyanthracene, hydroquinone, catechol, 2,2-bis (4-hydroxyphenyl) butane (hereinafter referred to as bisphenol B), 4,4-bis (4-hydroxyphenyl) valeric acid, 2 , 2-Bis (4-hydroxyphenyl) Tetrafluorodichloropropane, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl ketone, tri (4-hydroxyphenyl) methane, 3,3 ′, 5,5′-tetrachlorobisphenol A, 3,3 Examples include ', 5,5'-tetrabromobisphenol A. These polyhydroxy aromatic compounds may be an alkali metal salt, an alkaline earth metal salt or the like, but when the copolymer is coagulated using an acid, it is preferable not to use the metal salt.

  Among these, a polyhydroxy compound is preferable because the compression set such as a cross-linked product obtained is small and moldability is excellent, and a polyhydroxy aromatic compound is more preferable because of excellent heat resistance, and bisphenol AF is preferable. Further preferred.

  Moreover, in a polyol crosslinking system, it is usually preferable to include a crosslinking accelerator (E2). When a crosslinking accelerator is used, the crosslinking reaction can be promoted by promoting the formation of intramolecular double bonds in the dehydrofluorination reaction of the fluororubber main chain and the addition of polyhydroxy compounds to the generated double bonds. it can.

  An onium compound is generally used as the polyol crosslinking accelerator (E2). The onium compound is not particularly limited, and examples thereof include ammonium compounds such as quaternary ammonium salts, phosphonium compounds such as quaternary phosphonium salts, oxonium compounds, sulfonium compounds, cyclic amines, and monofunctional amine compounds. Of these, quaternary ammonium salts and quaternary phosphonium salts are preferred.

  The quaternary ammonium salt is not particularly limited. For example, 8-methyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-methyl-1,8-diazabicyclo [5, 4,0] -7-undecenium iodide, 8-methyl-1,8-diazabicyclo [5,4,0] -7-undecenium hydroxide, 8-methyl-1,8-diazabicyclo [5 , 4,0] -7-Undecenium methyl sulfate, 8-ethyl-1,8-diazabicyclo [5,4,0] -7-undecenium bromide, 8-propyl-1,8-diazabicyclo [5 , 4,0] -7-undecenium bromide, 8-dodecyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-dodecyl-1,8-diazabicyclo [5 4,0] -7-undecenium hydroxide, 8-eicosyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8-tetracosyl-1,8-diazabicyclo [5, 4,0] -7-undecenium chloride, 8-benzyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride (hereinafter referred to as DBU-B), 8-benzyl-1 , 8-diazabicyclo [5,4,0] -7-undecenium hydroxide, 8-phenethyl-1,8-diazabicyclo [5,4,0] -7-undecenium chloride, 8- (3- Phenylpropyl) -1,8-diazabicyclo [5,4,0] -7-undecenium chloride and the like. Among these, DBU-B is preferable from the viewpoint of crosslinkability and physical properties of the cross-linked product.

  The quaternary phosphonium salt is not particularly limited. For example, tetrabutylphosphonium chloride, benzyltriphenylphosphonium chloride (hereinafter referred to as BTPPC), benzyltrimethylphosphonium chloride, benzyltributylphosphonium chloride, tributylallylphosphonium chloride, tributyl. -2-Methoxypropylphosphonium chloride, benzylphenyl (dimethylamino) phosphonium chloride, and the like can be mentioned. Among these, benzyltriphenylphosphonium chloride (BTPPC) is preferred from the viewpoint of crosslinkability and physical properties of the cross-linked product.

  Further, as the crosslinking accelerator (E2), a quaternary ammonium salt, a solid solution of a quaternary phosphonium salt and bisphenol AF, or a chlorine-free crosslinking accelerator disclosed in JP-A-11-147891 can be used.

  As the fluororubber (A) suitable for the polyol crosslinking system, any of a perfluoro fluororubber and a non-perfluorofluororubber containing at least a TFE unit, a VdF unit, or a fluoromonomer unit of the formula (1) can be used. However, VdF rubber and TFE / Pr rubber are particularly preferable.

  As a compounding quantity of a polyol crosslinking agent, it is preferable that it is 0.01-10 mass parts with respect to 100 mass parts of fluororubber (A), More preferably, it is 0.1-7 mass parts. When the polyol crosslinking agent is less than 0.01 part by mass, the crosslinking of the fluororubber (A) tends not to proceed sufficiently, and when it exceeds 10 parts by mass, the balance of physical properties tends to be lowered.

  Moreover, it is preferable that the compounding quantity of a crosslinking accelerator (E2) is 0.01-8 mass parts with respect to 100 mass parts of fluororubber (A), More preferably, it is 0.02-5 mass parts. . When the crosslinking accelerator is less than 0.01 parts by mass, the crosslinking of the fluororubber (A) tends not to proceed sufficiently, and when it exceeds 8 parts by mass, the balance of physical properties tends to decrease.

(Polyamine crosslinking system)
When crosslinked by polyamine crosslinking, it has a carbon-nitrogen double bond at the crosslinking point and is characterized by excellent dynamic mechanical properties. However, the compression set tends to be larger than when crosslinking is performed using a polyol crosslinking system or a peroxide crosslinking system.

  Examples of the polyamine-based crosslinking agent include polyamine compounds such as hexamethylenediamine carbamate, N, N′-dicinnamylidene-1,6-hexamethylenediamine, and 4,4′-bis (aminocyclohexyl) methanecarbamate. Among these, N, N′-dicinnamylidene-1,6-hexamethylenediamine is preferable.

  As the fluororubber (A) suitable for the polyamine crosslinking system, any of a TFE unit, a VdF unit, or a perfluorofluororubber containing at least a fluorine-containing monomer unit of the formula (1) and a non-perfluorofluororubber can be used. However, VdF rubber and TFE / Pr rubber are particularly preferable.

  As a compounding quantity of a polyamine type crosslinking agent, it is preferable that it is 0.01-10 mass parts with respect to 100 mass parts of fluororubber (A), More preferably, it is 0.2-7 mass parts. When the polyamine crosslinking agent is less than 0.01 parts by mass, the crosslinking of the fluororubber (A) tends not to proceed sufficiently. When the polyamine crosslinking agent exceeds 10 parts by mass, the balance of physical properties tends to decrease.

(Oxazole crosslinking system, thiazole crosslinking system, imidazole crosslinking system)
The oxazole crosslinking system, thiazole crosslinking system, and imidazole crosslinking system are crosslinking systems that have a small compression set and excellent heat resistance.

（式中、Ｒ^１は同じかまたは異なり、−ＮＨ_２、−ＮＨＲ^２、−ＯＨまたは−ＳＨであり、Ｒ^２はフッ素原子または１価の有機基である）で示される架橋性反応基を少なくとも２個含む化合物、式（２５）：

で示される化合物、式（２６）：

（式中、Ｒ_ｆ ^１は炭素数１〜１０のパーフルオロアルキレン基）で示される化合物、および式（２７）：

（式中、ｎは１〜１０の整数）で示される化合物などが例示できる。As a crosslinking agent used for an oxazole crosslinking system, a thiazole crosslinking system, and an imidazole crosslinking system,
Formula (24):

(Wherein, R ¹ is the same or different and is —NH ₂ , —NHR ² , —OH or —SH, and R ² is a fluorine atom or a monovalent organic group). A compound comprising at least two compounds of formula (25):

A compound of formula (26):

(Wherein R _f ¹ is a perfluoroalkylene group having 1 to 10 carbon atoms) and formula (27):

(Wherein, n is an integer of 1 to 10).

（式中、Ｒ^１は前記と同じ、Ｒ^５は、−ＳＯ_２−、−Ｏ−、−ＣＯ−、炭素数１〜６のアルキレン基、炭素数１〜１０のパーフルオロアルキレン基、単結合手、または

で示される基である）で示される化合物や、２，２−ビス（３−アミノ−４−ヒドロキシフェニル）ヘキサフルオロプロパン、２，２−ビス（３−アミノ−４−メルカプトフェニル）ヘキサフルオロプロパン、２，２−ビス（３，４−ジアミノフェニル）ヘキサフルオロプロパンなどのほか、
式（２９）：

（式中、Ｒ^６は同じかまたは異なり、いずれも炭素数１〜１０のアルキル基；フッ素原子を含有する炭素数１〜１０のアルキル基；フェニル基；ベンジル基；フッ素原子および／または−ＣＦ_３で１〜５個の水素原子が置換されたフェニル基またはベンジル基である）で示される化合物が挙げられる。As a specific crosslinking agent, general formula (28) having two crosslinkable reactive groups represented by formula (24):

(In the formula, R ¹ is the same as described above, R ⁵ is —SO ₂ —, —O—, —CO—, an alkylene group having 1 to 6 carbon atoms, a perfluoroalkylene group having 1 to 10 carbon atoms, and a single bond. Hand, or

Or a compound represented by 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2-bis (3-amino-4-mercaptophenyl) hexafluoropropane , 2,2-bis (3,4-diaminophenyl) hexafluoropropane,
Formula (29):

Wherein R ⁶ is the same or different and both are alkyl groups having 1 to 10 carbon atoms; alkyl groups having 1 to 10 carbon atoms containing fluorine atoms; phenyl groups; benzyl groups; fluorine atoms and / or —CF ₃ is a phenyl group or a benzyl group in which 1 to 5 hydrogen atoms are substituted.

  Specific examples of these include, but are not limited to, for example, 2,2-bis (3,4-diaminophenyl) hexafluoropropane, 2,2-bis [3-amino-4- (N-methylamino) phenyl. ] Hexafluoropropane, 2,2-bis [3-amino-4- (N-ethylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N-propylamino) phenyl] hexa Fluoropropane, 2,2-bis [3-amino-4- (N-phenylamino) phenyl] hexafluoropropane, 2,2-bis [3-amino-4- (N-perfluorophenylamino) phenyl] hexa Bisaminophenol-based racks such as fluoropropane and 2,2-bis [3-amino-4- (N-benzylamino) phenyl] hexafluoropropane Agents and the like.

  Among the above crosslinking agents, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (OH-AF), 2 is preferable because of its excellent heat resistance and particularly good crosslinking reactivity. , 2-bis [3-amino-4- (N-phenylamino) phenyl] hexafluoropropane (Nph-AF), 2,2-bis (3,4-diaminophenyl) hexafluoropropane (TA-AF) Further preferred.

  Moreover, in these oxazole crosslinking systems, thiazole crosslinking systems, and imidazole crosslinking systems, a crosslinking aid (F) may be used in combination because the crosslinking rate is greatly improved.

  Examples of the crosslinking aid (F) used in combination with the oxazole crosslinking system, thiazole crosslinking system, and imidazole crosslinking system include (F1) a compound that generates ammonia at 40 to 330 ° C., and (F2) inorganic nitride particles.

(F1) Compound that generates ammonia at 40 to 330 ° C. (ammonia generating compound)
The ammonia generating compound (F1) is cured by causing the crosslinking generated by the ammonia generated at the crosslinking reaction temperature (40 to 330 ° C.) and also promoting the curing by the crosslinking agent. Some also react with a small amount of water to generate ammonia.

  Preferred examples of the ammonia generating compound (F1) include urea, derivatives thereof, and ammonium salts. The ammonium salt may be an organic ammonium salt or an inorganic ammonium salt.

  Urea derivatives include urea as well as biurea, thiourea, urea hydrochloride, biuret and the like.

  Examples of the organic ammonium salt include compounds described in JP-A-9-111101, WO 00/09603, WO 98/23675, such as ammonium perfluorohexanoate and ammonium perfluorooctanoate. Ammonium salt of polyfluorocarboxylic acid; ammonium salt of polyfluorosulfonic acid such as ammonium perfluorohexanesulfonate and ammonium perfluorooctanesulfonate; polyfluoroalkyl such as ammonium perfluorohexanephosphate and ammonium perfluorooctanephosphate Group-containing phosphoric acid, ammonium salt of phosphonic acid; non-fluorinated carboxylic acid such as ammonium benzoate, ammonium adipate, ammonium phthalate or sulfur Ammonium salts of phosphate can be exemplified. Among these, from the viewpoint of dispersibility, an ammonium salt of a fluorinated carboxylic acid, sulfonic acid or phosphoric acid is preferred. On the other hand, an ammonium salt of a non-fluorinated carboxylic acid, sulfonic acid or phosphoric acid is preferred from an inexpensive point of view. preferable.

  Examples of the inorganic ammonium salt include compounds described in JP-A-9-111101, such as ammonium sulfate, ammonium carbonate, ammonium nitrate, and ammonium phosphate. Among them, ammonium phosphate is preferable in consideration of vulcanization characteristics.

In addition, acetaldehyde ammonia, hexamethylenetetramine, formamidine, formamidine hydrochloride, formamidine acetate, t- butyl carbamate, benzyl _{carbamate, HCF 2 CF 2 CH (CH} 3) OCONH 2, phthalamide, etc. can be used.

  These ammonia generating compounds (F1) may be used alone or in combination of two or more.

(F2) Inorganic nitride particles The inorganic nitride particles (F2) are not particularly limited, but include silicon nitride (Si ₃ N ₄ ), lithium nitride, titanium nitride, aluminum nitride, boron nitride, vanadium nitride, Examples include zirconium nitride. Among these, silicon nitride particles are preferable because nano-sized fine particles can be supplied. These nitride particles may be used in combination of two or more.

  The particle size of the inorganic nitride particles (F2) is not particularly limited, but is preferably 1000 nm or less, more preferably 300 nm or less, and still more preferably 100 nm or less. The lower limit is not particularly limited.

  These inorganic nitride particles (F2) may be used in combination with an ammonia generating compound (F1).

  These oxazole crosslinking systems, thiazole crosslinking systems, and imidazole crosslinking systems are targeted for the following VdF rubbers having a specific crosslinkable group and TFE / Pr rubbers having a specific crosslinkable group.

(VdF rubber having specific crosslinkable group)
The specific VdF rubber contains VdF, at least one (per) fluoroolefin selected from the group consisting of TFE, HFP and (per) fluoro (vinyl ether), and a cyano group, a carboxyl group or an alkoxycarbonyl group. It is a VdF rubber that is a copolymer with a monomer.

  However, it is important for the VdF copolymerization ratio to exceed 20 mol% in order to improve vulnerability at low temperatures.

As (per) fluoro (vinyl ether), general formula (30):
^{_{CF 2 = CFO (CF 2 CFY}} 2 O) p - (CF 2 CF 2 CF 2 O) q -R f 5 (30)
(In the formula, Y ² represents a fluorine atom or —CF ₃ , R _f ⁵ represents a perfluoroalkyl group having 1 to 5 carbon atoms, p represents an integer of 0 to 5, and q represents 0 to 0. Represents an integer of 5.)
Or, general formula (31):
CFX = CXOCF ₂ OR (31)
(Wherein X is F or H; R is a linear or branched fluoroalkyl group having 1 to 6 carbon atoms, a cyclic fluoroalkyl group having 5 to 6 carbon atoms, or a fluorooxyalkyl group. , Cl, Br, or I may be selected from one or two atoms selected from Cl, Br, and I).

  Among those represented by the general formula (30) and the general formula (31), perfluoro (methyl vinyl ether) and perfluoro (propyl vinyl ether) are preferable, and perfluoro (methyl vinyl ether) is particularly preferable.

  These can be used alone or in any combination.

  The copolymerization ratio of VdF and specific perfluoroolefin may be such that VdF exceeds 20 mol%, and in particular, VdF consisting of 45 to 85 mol% of VdF and 55 to 15 mol% of specific perfluoroolefin. The rubber is preferably a VdF rubber composed of 50 to 80 mol% of VdF and 50 to 20 mol% of a specific perfluoroolefin.

  Specific examples of combinations of VdF and specific perfluoroolefins include VdF / HFP copolymer, VdF / HFP / TFE copolymer, VdF / PAVE copolymer, and VdF / TFE / PAVE copolymer. It is preferably at least one selected from the group consisting of a polymer, a VdF / HFP / PAVE copolymer, and a VdF / HFP / TFE / PAVE copolymer.

  The VdF / HFP copolymer preferably has a VdF / HFP composition of 45 to 85/55 to 15 mol%, more preferably 50 to 80/50 to 20 mol%, still more preferably, 60 to 80/40 to 20 mol%.

  The VdF / TFE / HFP copolymer preferably has a VdF / TFE / HFP composition of 40 to 80/10 to 35/10 to 35 mol%.

  The VdF / PAVE copolymer preferably has a VdF / PAVE composition of 65 to 90/35 to 10 mol%.

  As a VdF / TFE / PAVE copolymer, the composition of VdF / TFE / PAVE is preferably 40 to 80/3 to 40/15 to 35 mol%.

  The VdF / HFP / PAVE copolymer preferably has a VdF / HFP / PAVE composition of 65 to 90/3 to 25/3 to 25 mol%.

  As VdF / HFP / TFE / PAVE copolymer, the composition of VdF / HFP / TFE / PAVE is preferably 40 to 90/0 to 25/0 to 40/3 to 35, preferably 40 to 80/3 to 25 More preferred are those of / 3 to 40/3 to 25 mol%.

  The monomer containing a cyano group, a carboxyl group or an alkoxycarbonyl group is 0.1 to 5 mol% based on the total amount of VdF and a specific perfluoroolefin from the viewpoint of good crosslinking properties and heat resistance. It is preferable that it is 0.3 to 3 mol%.

Examples of the monomer containing a cyano group, a carboxyl group, or an alkoxycarbonyl group include, for example, formulas (32) to (35):
CY ¹ ₂ = CY ¹ (CF ₂ ) _n −X ¹ (32)
(Wherein, Y ¹ are the same or different, a hydrogen atom or a fluorine atom, n represents an integer from 1 to 8)
^{_{CF 2 = CFCF 2 R f 6}} -X 1 (33)
(Wherein R _f ⁶ represents — (OCF ₂ ) _n —, — (OCF (CF ₃ )) _n —
And n is an integer from 0 to 5)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m O (CF 2) n -X 1 (34)
(In the formula, m is an integer of 0 to 5, and n is an integer of 1 to 8.)
_{CF 2 = CF (OCF 2 CF} (CF 3)) m -X 1 (35)
(Where m is an integer from 1 to 5)
(In the formulas (32) to (35), X ¹ is a cyano group (—CN group), a carboxyl group (—COOH group), or an alkoxycarbonyl group (—COOR group, R is a fluorine atom having 1 to 10 carbon atoms). And the like, and the like. These monomers can be used alone or in any combination.

  These VdF rubbers having specific crosslinkable groups can be produced by a conventional method.

  As a method for introducing these crosslinkable groups, the method described in International Publication No. 00/05959 pamphlet can also be used.

Moreover, the VdF rubber having a specific crosslinkable group has a Mooney viscosity (ML _{1 + 10} (121 ° C.)) of 5 to 140, more preferably 5 to 120, and particularly 5 to 100 from the viewpoint of good processability. Is preferred.

(TFE / Pr rubber having specific crosslinkable group)
The TFE / Pr rubber having a specific crosslinkable group is a non-perfluoro having a TFE unit of 40 to 70 mol%, a Pr unit of 30 to 60 mol%, and a monomer unit having a cyano group, a carboxyl group or an alkoxycarbonyl group. It is rubber.

  Moreover, 0-15 mol% of VdF units and / or 0-15 mol% of PAVE units may be included as needed.

  The TFE unit is 40 to 70 mol%, preferably 50 to 65 mol%, and an elastomeric property is obtained in this range.

  The Pr unit is 30 to 60 mol%, preferably 35 to 50 mol%, and elastomeric properties can be obtained in TFE and this range.

  Examples of the monomer having a cyano group, a carboxyl group, or an alkoxycarbonyl group include TFE / Pr having a specific crosslinkable group, including those described in the VdF rubber having a specific crosslinkable group. Can also be used for rubber.

  VdF units or PAVE units, which are arbitrary units, are up to 15 mol%, further up to 10 mol%, and beyond this, the former is not preferable in terms of amine resistance and the latter is high in cost.

Further, the TFE / Pr rubber having a specific crosslinkable group has a Mooney viscosity (ML _{1 + 10} (121 ° C.)) of 5 to 100. When the Mooney viscosity is less than 5, the vulcanizability is lowered and sufficient physical properties as a vulcanized rubber are not produced, and when it exceeds 100, the fluidity is lowered and the moldability tends to be deteriorated. A preferable Mooney viscosity (ML _{1 + 10} (121 ° C.)) is 10 to 80.

  A TFE / Pr rubber having a specific crosslinkable group can be produced by an ordinary emulsion polymerization method. However, since the polymerization rate of TFE and Pr is relatively slow, for example, when producing by a two-stage polymerization method (seed polymerization method). Can be manufactured efficiently.

  The amount of these oxazole-based, thiazole-based and imidazole-based crosslinking agents added is preferably 0.1 to 20 parts by mass, and 0.5 to 10 parts by mass with respect to 100 parts by mass of the specific fluororubber. More preferably. If the cross-linking agent is less than 0.1 parts by mass, there is a tendency that practically sufficient mechanical strength, heat resistance and chemical resistance cannot be obtained, and if it exceeds 20 parts by mass, it takes a long time to cross-link. The cross-linked product tends to be hard and not flexible.

  When the crosslinking aid (F) is used in combination with these oxazole crosslinking system, thiazole crosslinking system, and imidazole crosslinking system, the addition amount of the crosslinking assistant (F) is usually based on 100 parts by mass of the specific fluororubber. It is 0.01-10 mass parts, it is preferable that it is 0.02-5 mass parts, and it is more preferable that it is 0.05-3 mass parts.

(Triazine crosslinking system)
The triazine crosslinking system is a crosslinking system having a small compression set and excellent heat resistance. In the triazine crosslinking system, only the crosslinking aid (F) that initiates the crosslinking reaction is used.

  As the crosslinking aid (F) used in the triazine crosslinking system, for example, in the above oxazole crosslinking system, thiazole crosslinking system and imidazole crosslinking system, it is a crosslinking aid that can be used in combination with the crosslinking agent (F1). Generates ammonia at 40 to 330 ° C. The compound to be made or (F2) inorganic nitride particles can be exemplified.

  The triazine crosslinking system is preferably a fluororubber in which at least one of the crosslinkable groups is a cyano group among the fluororubbers having a specific crosslinkable group targeted by the oxazole crosslinking system, thiazole crosslinking system, and imidazole crosslinking system.

  The addition amount of the ammonia generating compound (F1) may be appropriately selected depending on the amount of generated ammonia, but is usually 0.05 to 10 parts by mass with respect to 100 parts by mass of the cyano group-containing fluororubber. It is preferably 1 to 5 parts by mass, and more preferably 0.2 to 3 parts by mass. If the amount of the ammonia generating compound is too small, the crosslinking density is lowered, so that there is a tendency that the practically sufficient heat resistance and chemical resistance are not expressed. If the amount is too large, there is a concern of scorching and storage stability is deteriorated. Tend.

  The addition amount of the inorganic nitride particles (F2) is 0.1 to 20 parts by mass, preferably 0.2 to 5 parts by mass with respect to 100 parts by mass of the cyano group-containing fluororubber. More preferably, it is 2-1 mass part. When the inorganic nitride particles (F2) are less than 0.1 parts by mass, the vulcanization density is low, and thus there is a tendency that practically sufficient heat resistance and chemical resistance are not exhibited. , There is a concern of scorching, and the storage stability tends to be poor.

  In the present invention, a peroxide crosslinking system, a polyol crosslinking system, an oxazole crosslinking system, a thiazole crosslinking system, an imidazole crosslinking system, or a triazine crosslinking system is preferable as the crosslinking system, and a crosslinking agent (D) suitable for each crosslinking system, It is preferable to use a crosslinking accelerator (E) or a crosslinking assistant (F). Among these, it is more preferable to use a crosslinking agent of a peroxide crosslinking system, an oxazole crosslinking system, a thiazole crosslinking system and an imidazole crosslinking system, or a triazine crosslinking system.

  In the present invention, a normal rubber compound such as a filler, a processing aid, a plasticizer, a colorant, an adhesion aid, an acid acceptor, a pigment, a flame retardant, and a lubricant as necessary for the fluororubber composition. , Light stabilizers, weathering stabilizers, antistatic agents, UV absorbers, antioxidants, mold release agents, foaming agents, fragrances, oils, softeners, polyethylene, polypropylene, polyamide, polyester, polyurethane, etc. You may mix | blend polymer etc. in the range which does not impair the effect of this invention.

  Fillers include metal oxides such as calcium oxide, magnesium oxide, titanium oxide, and aluminum oxide; metal hydroxides such as magnesium hydroxide, aluminum hydroxide, and calcium hydroxide; magnesium carbonate, aluminum carbonate, calcium carbonate, carbonic acid Carbonates such as barium; silicates such as magnesium silicate, calcium silicate, sodium silicate, and aluminum silicate; sulfates such as aluminum sulfate, calcium sulfate, and barium sulfate; synthetic hydrotalcite; molybdenum disulfide, sulfide Metal sulfides such as iron and copper sulfide; diatomaceous earth, asbestos, lithopone (zinc sulfide / barium sulfide), graphite, carbon fluoride, calcium fluoride, coke, quartz fine powder, talc, mica powder, wollastonite, Carbon fiber, aramid fiber, various types Scar, glass fibers, organic reinforcing agents, organic fillers, polytetrafluoroethylene, mica, silica, celite, clays, and others.

  As processing aids, higher fatty acids such as stearic acid, oleic acid, palmitic acid and lauric acid; higher fatty acid salts such as sodium stearate and zinc stearate; higher fatty acid amides such as stearic acid amide and oleic acid amide; oleic acid Higher fatty acid esters such as ethyl; Petroleum waxes such as carnauba wax and ceresin wax; Polyglycols such as ethylene glycol, glycerin and diethylene glycol; Aliphatic hydrocarbons such as petroleum jelly and paraffin; Silicone oils, silicone polymers, low molecular weight polyethylene Phthalic acid esters, phosphoric acid esters, rosin, (halogenated) dialkylamines, surfactants, sulfone compounds, fluorine-based auxiliaries and the like.

  In addition, when mix | blending a crosslinking agent etc. with the fluororubber composition prepared by the method of said (1) and (2), you may mix | blend an alkylamine compound and / or an acid acceptor further. The alkylamine compound blended in the kneading step such as the crosslinking agent may be the same as or different from the organic amine compound (C1) blended in the methods (1) and (2). The blending amount is preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the fluororubber (A). Moreover, when mix | blending an acid acceptor, it may be the same as that of the acid acceptor (C2) mix | blended in the method of said (1) and (2), or may differ. The blending amount is preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the fluororubber (A).

  The cross-linking method of the fluororubber composition obtained by the production method of the present invention may be appropriately selected. For example, a normal cross-linking method such as an extrusion method, a press method or an injection method can be employed. Moreover, when bridge | crosslinking to tubular forms, such as a hose, the bridge | crosslinking method using a bridge | crosslinking can etc. are employ | adopted. Further, a molding method such as extrusion molding or steaming molding can also be employed. If secondary crosslinking is required depending on the purpose of use of the crosslinked product, oven crosslinking may be further performed.

  The obtained cross-linked fluororubber also has a dynamic viscoelasticity test (measurement mode: tensile, distance between chucks: 20 mm, tensile strain: 1%, measurement frequency: 10 Hz, initial load: 157 cN, measurement temperature: 160 ° C.) When the loss elastic modulus E ″ is 400 kPa or more and 6000 kPa or less, the normal physical properties and the mechanical properties at high temperatures are particularly excellent.

  When the loss elastic modulus E ″ is in the above range, it is particularly excellent in normal properties and mechanical properties at high temperature, etc. The lower limit is preferably 420 kPa, more preferably 430 kPa, and the upper limit is preferably 5900 kPa. More preferably, it is 5800 kPa.

  In addition, the obtained fluororubber crosslinked product has a dynamic viscoelasticity test (measurement mode: tension, distance between chucks: 20 mm, measurement temperature: 160 ° C., tensile strain: 1%, initial load: 157 cN, frequency: 10 Hz). The storage elastic modulus E ′ is more preferably 1500 kPa or more and 20000 kPa or less from the viewpoint of improvement in mechanical properties at high temperatures. The lower limit is preferably 1600 kPa, more preferably 1800 kPa, and the upper limit is preferably 19000 kPa, more preferably 18000 kPa.

  Further, the cross-linked fluororubber has a tensile elongation at break of 100 to 700%, further 110% or more, particularly 120% or more, and 680% or less, particularly 650% or less at 160 ° C. This is preferable because it is suitable for use in an environment.

  Further, the cross-linked fluororubber has a tensile breaking strength at 160 ° C. of 1 MPa or more, more preferably 1.5 MPa or more, particularly 2 MPa or more, and 30 MPa or less, particularly 28 MPa or less. This is preferable because it is suitable for use.

  Further, the cross-linked fluororubber has a tear strength of 3 to 30 kN / m, further 4 kN / m or more, particularly 5 kN / m or more, 29 kN / m or less, particularly 28 kN / m or less at 160 ° C. Is preferable because it is suitable for use in a high-temperature environment.

  Further, the cross-linked fluororubber has a tensile elongation at break of 100 to 700%, further 110% or more, particularly 120% or more, and 680% or less, particularly 650% or less at 200 ° C. This is preferable because it is suitable for use in an environment.

  Further, the crosslinked fluororubber has a tensile breaking strength at 200 ° C. of 1 to 30 MPa, more preferably 1.5 MPa or more, particularly 2 MPa or more, and 29 MPa or less, particularly 28 MPa or less in a high temperature environment. It is preferable because it is suitable for use in the above. The tensile breaking strength and the tensile breaking elongation are measured using a No. 6 dumbbell according to JIS-K6251.

  The crosslinked fluororubber has a tear strength at 200 ° C. of 3 to 30 kN / m, further 4 kN / m or more, particularly 5 kN / m or more, 29 kN / m or less, particularly 28 kN / m or less. Is preferable because it is suitable for use in a high-temperature environment.

  The fluororubber cross-linked product having such characteristics can be suitably used for various applications as follows, for example.

(1) Hose As the hose, a hose having a single-layer structure composed only of a cross-linked fluororubber obtained by cross-linking the fluororubber composition of the present invention may be used, or a multi-layer hose having a laminated structure with other layers It may be.

  Examples of the single-layered hose include an exhaust gas hose, an EGR hose, a turbocharger hose, a fuel hose, a brake hose, and an oil hose.

  Examples of the multi-layered hose include an exhaust gas hose, an EGR hose, a turbocharger hose, a fuel hose, a brake hose, and an oil hose.

  A turbo system is often installed in a diesel engine. By sending exhaust gas from the engine to the turbine and rotating it, the compressor connected to the turbine is moved to increase the compression ratio of the air supplied to the engine and improve the output. It is. This turbo system that uses the exhaust gas of the engine and obtains a high output leads to a reduction in the size of the engine, a reduction in fuel consumption of the automobile, and a cleaner exhaust gas.

  The turbocharger hose is used in the turbo system as a hose for sending compressed air to the engine. In order to effectively utilize the space in a narrow engine room, a rubber hose with excellent flexibility and flexibility is advantageous, and typically rubber with excellent heat aging resistance and oil resistance (especially fluororubber) ) A hose having a multilayer structure in which the layer is an inner layer and silicone rubber or acrylic rubber is an outer layer is employed. However, the engine surroundings such as the engine room are exposed to high temperatures and are in a harsh environment where vibration is also applied, and not only heat aging resistance but also excellent mechanical properties at high temperatures are required.

  The hose satisfies these required characteristics at a high level by using a cross-linked fluororubber layer obtained by cross-linking the fluororubber composition of the present invention as a single layer and a multi-layer rubber layer. A turbocharger hose having characteristics can be provided.

  In a hose having a multilayer structure other than a turbocharger hose, examples of the layer made of other materials include a layer made of other rubber, a layer made of a thermoplastic resin, various fiber reinforcing layers, a metal foil layer, and the like.

  As other rubbers, acrylonitrile-butadiene rubber or its hydrogenated rubber, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, fluorine rubber, epichlorohydrin rubber, when chemical resistance and flexibility are particularly required A rubber comprising at least one selected from the group consisting of EPDM and acrylic rubber is preferred, and acrylonitrile-butadiene rubber or hydrogenated rubber thereof, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, fluorine rubber, epichlorohydrin rubber More preferably, it is made of at least one rubber selected from the group consisting of:

  The thermoplastic resin is a heat composed of at least one selected from the group consisting of fluororesins, polyamide resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, polyvinyl chloride resins, and polyphenylene sulfide resins. A plastic resin is preferable, and a thermoplastic resin made of at least one selected from the group consisting of a fluororesin, a polyamide resin, a polyvinyl alcohol resin, and a polyphenylene sulfide resin is more preferable.

  Moreover, when producing the hose of a multilayer structure, you may surface-treat as needed. The type of the surface treatment is not particularly limited as long as it is a treatment method that enables adhesion. For example, discharge treatment such as plasma discharge treatment or corona discharge treatment, wet metal sodium / naphthalene liquid treatment Etc. A primer treatment is also suitable as the surface treatment. Primer treatment can be performed according to a conventional method. When the primer treatment is applied, the surface of the fluororubber that has not been surface-treated can be treated, but if the primer treatment is further performed after plasma discharge treatment, corona discharge treatment, metal sodium / naphthalene liquid treatment, etc. are performed in advance. Is more effective.

  In addition, the hose using the crosslinked product of the present invention can be suitably used in the following fields.

  In semiconductor manufacturing related fields such as semiconductor manufacturing equipment, liquid crystal panel manufacturing equipment, plasma panel manufacturing equipment, plasma addressed liquid crystal panels, field emission display panels, solar cell substrates, etc., CVD equipment, dry etching equipment, wet etching exposed to high temperature environments It can be used for hoses such as an apparatus, an oxidation diffusion apparatus, a sputtering apparatus, an ashing apparatus, a cleaning apparatus, an ion implantation apparatus, and an exhaust apparatus.

  In the automobile field, it can be used as a peripheral device for engines and automatic transmissions, and can be used as a turbocharger hose, an EGR hose, an exhaust gas hose, a fuel hose, an oil hose, a brake hose, and the like.

  In addition, it can also be used for hoses in the aircraft field, rocket field and ship field, chemical plant field, analytical / physical machine field, food plant equipment field, nuclear power plant equipment field and the like.

(2) Sealing material The sealing material can be suitably used in the following fields.

  For example, engine body, main motion system, valve system, lubricant / cooling system, fuel system, intake / exhaust system; drive system transmission system; chassis steering system; brake system; Gaskets that require heat resistance, oil resistance, fuel oil resistance, engine cooling antifreeze resistance, steam resistance, non-contact type and contact type packing (self-sealing packing) , Piston rings, split ring packings, mechanical seals, oil seals, etc.).

  The sealing material used in the engine body of the automobile engine is not particularly limited. For example, a cylinder head gasket, a cylinder head cover gasket, an oil pan packing, a gasket such as a general gasket, an O-ring, a packing, a timing belt cover gasket, etc. A sealing material etc. are mentioned.

  The seal material used for the main motion system of the automobile engine is not particularly limited, and examples thereof include a shaft seal such as a crankshaft seal and a camshaft seal.

  The seal material used for the valve system of the automobile engine is not particularly limited, and examples thereof include a valve stem oil seal for an engine valve and a valve seat for a butterfly valve.

  The seal material used for the lubricant / cooling system of the automobile engine is not particularly limited, and examples thereof include a seal gasket of an engine oil cooler.

  The sealing material used in the engine fuel system for automobiles is not particularly limited. For example, fuel injection such as an oil seal of a fuel pump, a filler seal of a fuel tank, a tank packing, a connector O link of a fuel tube, etc. Examples thereof include EGR sealing materials such as an injector cushion ring, an injector seal ring, an injector O-ring, and a carburetor flange gasket.

  The sealing material used for the intake / exhaust system of the automobile engine is not particularly limited. For example, the intake manifold packing of the manifold, the exhaust manifold packing, the throttle body packing of the throttle, the turbine shaft seal of the turbo charge, etc. Is mentioned.

  The seal material used in the transmission system for automobiles is not particularly limited, and examples thereof include bearing seals, oil seals, O-rings and packings for transmissions, and O-rings and packings for automatic transmissions. It is done.

  The sealing material used in the brake system for automobiles is not particularly limited. For example, oil seals, O-rings, packing, etc., master cylinder piston cups (rubber cups), caliper seals, boots, etc. Is mentioned.

  The sealing material used for the electrical equipment for automobiles is not particularly limited, and examples thereof include O-rings and packings for car air conditioners.

  Especially as a sealing material, it is suitable for the sealing material for sensors (bush), Furthermore, it is suitable for the sealing material for oxygen sensors, the sealing material for nitrogen oxide sensors, the sealing material for sulfur oxide sensors, etc. The O-ring may be a square ring.

  Applications other than the automotive field are not particularly limited, and include aircraft field, rocket field, ship field, oil field drilling field (for example, packer seals, MWD seals, LWD seals, etc.), chemicals such as plants, pharmaceuticals, etc. Chemical field, photographic field such as developing machine, printing field such as printing machine, coating field such as coating equipment, analytical / physical machine field, food plant equipment field, nuclear power plant equipment field, steel field such as iron plate processing equipment, general industry It can be widely used in fields such as the field, electrical field, fuel cell field, electronic component field and on-site construction mold forming.

  For example, oil-resistant, chemical-resistant, heat-resistant, steam- or weather-resistant packings, O-rings, and other sealing materials in transportation such as ships and aircraft; similar packing, O-rings, sealing materials in oilfield drilling; Packing, O-rings, sealing materials for food plants, and similar packings, O-rings, sealing materials for food plant equipment (including household products); similar packings, O-rings, sealing materials for nuclear plant equipment; The same packing, O-ring, sealing material and the like can be mentioned.

(3) Belt The fluororubber crosslinked product of the present invention can be suitably used for the belt shown below.

  It can be used as a belt material for power transmission belts (including flat belts, V-belts, V-ribbed belts, toothed belts, etc.) and conveyor belts (conveyor belts). Also, in semiconductor manufacturing related fields such as semiconductor manufacturing equipment, liquid crystal panel manufacturing equipment, plasma panel manufacturing equipment, plasma addressed liquid crystal panels, field emission display panels, solar cell substrates, CVD equipment, dry etching equipment exposed to high temperature environments, It can be used for belt materials such as a wet etching apparatus, an oxidation diffusion apparatus, a sputtering apparatus, an ashing apparatus, a cleaning apparatus, an ion implantation apparatus, and an exhaust apparatus.

  Examples of the flat belt include flat belts used for various high-temperature sites such as around the engine of agricultural machines, machine tools, industrial machines, and the like. As conveyor belts, for example, conveyor belts for conveying loose and granular materials such as coal, crushed stone, earth and sand, ore, and wood chips in a high temperature environment, conveyor belts used in steelworks such as blast furnaces, precision Examples include conveyor belts in applications exposed to high-temperature environments in equipment assembly factories, food factories, and the like. Examples of the V belt and V ribbed belt include agricultural machinery, general equipment (OA equipment, printing machines, commercial dryers, etc.), automobile V belts, and V ribbed belts. Examples of the toothed belt include a toothed belt such as a power transmission belt of a transfer robot, a food machine, and a power transmission belt of a machine tool, and a toothed belt used in automobiles, OA equipment, medical use, printing machines, and the like. Can be mentioned. In particular, a timing belt is mentioned as a toothed belt for automobiles.

  In the multilayer belt material, examples of the layer made of another material include a layer made of other rubber, a layer made of a thermoplastic resin, various fiber reinforced layers, a canvas, and a metal foil layer.

  As other rubbers, acrylonitrile-butadiene rubber or its hydrogenated rubber, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, fluorine rubber, epichlorohydrin rubber, when chemical resistance and flexibility are particularly required A rubber comprising at least one selected from the group consisting of EPDM and acrylic rubber is preferred, and acrylonitrile-butadiene rubber or hydrogenated rubber thereof, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, fluorine rubber, epichlorohydrin rubber More preferably, it is made of at least one rubber selected from the group consisting of:

  The thermoplastic resin is a heat composed of at least one selected from the group consisting of fluororesins, polyamide resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, polyvinyl chloride resins, and polyphenylene sulfide resins. A plastic resin is preferable, and a thermoplastic resin made of at least one selected from the group consisting of a fluororesin, a polyamide resin, a polyvinyl alcohol resin, and a polyphenylene sulfide resin is more preferable.

  Moreover, when producing the belt material of a multilayer structure, you may surface-treat as needed. The type of the surface treatment is not particularly limited as long as it is a treatment method that enables adhesion. For example, discharge treatment such as plasma discharge treatment or corona discharge treatment, wet metal sodium / naphthalene liquid treatment Etc. A primer treatment is also suitable as the surface treatment. Primer treatment can be performed according to a conventional method. When the primer treatment is applied, the surface of the fluororubber that has not been surface-treated can be treated, but if the primer treatment is further performed after plasma discharge treatment, corona discharge treatment, metal sodium / naphthalene liquid treatment, etc. are performed in advance. Is more effective.

(4) Anti-vibration rubber The fluororubber cross-linked product of the present invention satisfies the required characteristics for anti-vibration rubber at a high level by using it as a rubber layer of a single layer and a multilayer structure in anti-vibration rubber. An anti-vibration rubber for automobiles having characteristics can be provided.

  In the anti-vibration rubber having a multilayer structure other than the anti-vibration rubber for automobiles, examples of the layer made of other materials include a layer made of other rubber, a layer made of thermoplastic resin, various fiber reinforced layers, a metal foil layer, and the like. .

  As other rubbers, acrylonitrile-butadiene rubber or its hydrogenated rubber, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, fluorine rubber, epichlorohydrin rubber, when chemical resistance and flexibility are particularly required A rubber comprising at least one selected from the group consisting of EPDM and acrylic rubber is preferred, and acrylonitrile-butadiene rubber or hydrogenated rubber thereof, blend rubber of acrylonitrile-butadiene rubber and polyvinyl chloride, fluorine rubber, epichlorohydrin rubber More preferably, it is made of at least one rubber selected from the group consisting of:

  The thermoplastic resin is a heat composed of at least one selected from the group consisting of fluororesins, polyamide resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, polyvinyl chloride resins, and polyphenylene sulfide resins. A plastic resin is preferable, and a thermoplastic resin made of at least one selected from the group consisting of a fluororesin, a polyamide resin, a polyvinyl alcohol resin, and a polyphenylene sulfide resin is more preferable.

  Moreover, when producing the vibration-proof rubber of a multilayer structure, you may surface-treat as needed. The type of the surface treatment is not particularly limited as long as it is a treatment method that enables adhesion. For example, discharge treatment such as plasma discharge treatment or corona discharge treatment, wet metal sodium / naphthalene liquid treatment Etc. A primer treatment is also suitable as the surface treatment. Primer treatment can be performed according to a conventional method. When the primer treatment is applied, the surface of the fluororubber that has not been surface-treated can be treated, but if the primer treatment is further performed after plasma discharge treatment, corona discharge treatment, metal sodium / naphthalene liquid treatment, etc. are performed in advance. Is more effective.

(5) Diaphragm The fluororubber crosslinked product of the present invention can be suitably used for the following diaphragms.

For example, applications of automobile engines include diaphragms such as fuel systems, exhaust systems, brake systems, drive systems, and ignition systems that require heat resistance, oxidation resistance, fuel resistance, low gas permeability, and the like.

Examples of the diaphragm used in the fuel system of an automobile engine include a fuel pump diaphragm, a carburetor diaphragm, a pressure regulator diaphragm, a pulsation damper diaphragm, an ORVR diaphragm, a canister diaphragm, and an auto fuel cock diaphragm. .

Examples of the diaphragm used in the exhaust system of the automobile engine include a waste gate diaphragm, an actuator diaphragm, an EGR diaphragm, and the like.
Examples of the diaphragm used for the brake system of the automobile engine include an air brake diaphragm.
Examples of the diaphragm used in the drive system of the automobile engine include an oil pressure diaphragm.
Examples of the diaphragm used in the ignition system of the automobile engine include a distributor diaphragm.

Applications other than automotive engines that require heat resistance, oil resistance, chemical resistance, steam resistance, low gas permeability, etc. General pump diaphragms, valve diaphragms, filter press diaphragms, blower diaphragms, air conditioners Diaphragms for industrial equipment, diaphragms for control equipment, diaphragms for water supply, diaphragms used for pumps for supplying hot water for hot water supply, diaphragms for high-temperature steam, diaphragms for semiconductor devices (for example, transfer of chemicals used in manufacturing processes, etc.) Diaphragms for food processing equipment, diaphragms for liquid storage tanks, diaphragms for pressure switches, diaphragms used in oil exploration and oil drilling applications (for example, diaphragms for supplying lubricating oil such as oil drilling bits), gas water heaters, Gas meter Gas appliance diaphragm of the accumulator diaphragm, air spring diaphragm such as a suspension, a screw feeder diaphragm marine, and medical artificial heart diaphragm and the like.

  Next, the present invention will be described with reference to examples. However, the present invention is not limited to such examples.

  Various physical property measuring methods employed in the present invention are as follows.

(1) Dynamic viscoelasticity test (A) Dynamic viscoelasticity measurement at the time of non-crosslinking (shear elastic modulus G ′)
Method of measuring difference δG ′ between shear modulus G ′ (1%) when dynamic strain is 1% and shear modulus G ′ (100%) when dynamic strain is 100%
Using a rubber process analyzer (model: RPA2000) manufactured by Alpha Technologies, the dynamic viscoelasticity is measured at 100 ° C. and 1 Hz.
(B) Dynamic viscoelasticity measurement of crosslinked product (storage elastic modulus E ′ and loss elastic modulus E ″)
Measuring device: Dynamic viscoelasticity measuring device DVA-220 manufactured by IT Measurement Control Co., Ltd.
Measurement conditions Specimen: 3mm wide x 2mm thick rectangular cross-linked rubber Measurement mode: tension Distance between chucks: 20mm
Measurement temperature: 160 ° C
Tensile strain: 1%
Initial weight: 157 cN
Frequency: 10Hz

(2) Tensile strength at break and tensile elongation at break The tester uses RTA-1T manufactured by Orientec Co., Ltd. and AG-I manufactured by Shimadzu Corporation. In accordance with JIS-K6251, the tensile strength at break and tensile elongation at break are measured using a dumbbell set at 50 mm between the chucks and a tensile speed of 500 mm / min. Measurement temperature shall be 25 degreeC and 160 degreeC.

(3) High temperature tensile repetition test AG-I manufactured by Shimadzu Corporation is used as a tester. Tensile conditions are set in accordance with JIS-K6251, using a No. 6 dumbbell, a gap between chucks of 50 mm, and a chuck moving speed of 500 mm / min. Temperature control shall be 160 degreeC. 300% elongation was repeated and the number of cycles until breakage was measured.

(4) Mooney viscosity (ML _{1 + 10} (100 ° C.))
Mooney viscosity was measured in accordance with ASTM-D1646 and JIS K6300. The measurement temperature is 100 ° C.

  In the examples and comparative examples, the following fluororubber, carbon black, organic amine compound, peroxide crosslinking agent and crosslinking accelerator were used.

(Fluoro rubber)
A1: 8.8 g of pure water 44L, CH ₂ = CFCF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COONH _{4 in} a 82 L stainless steel autoclave, F (CF ₂ ) ₃ COONH ₄ 176 g of a 50% aqueous solution was charged, and the inside of the system was sufficiently replaced with nitrogen gas. After the temperature was raised to 80 ° C. while stirring at 230 rpm, the monomer was injected so that the initial monomer composition was VdF / HFP = 50/50 mol%, 1.52 MPa. Then, a polymerization initiator solution in which 1.0 g of APS was dissolved in 220 ml of pure water was injected with nitrogen gas to start the reaction. When the internal pressure dropped to 1.42 MPa as the polymerization proceeded, a mixed monomer of VdF / HFP = 78/22 mol% as an additional monomer was injected until the internal pressure became 1.52 MPa. At this time, 73 g of diiodine compound I (CF ₂ ) ₄ I was injected. While repeatedly increasing and decreasing the pressure, an aqueous solution of 1.0 g of APS / 220 ml of pure water was injected with nitrogen gas every 3 hours to continue the polymerization reaction. When 14000 g of mixed monomer was added, unreacted monomers were released, and the autoclave was cooled to obtain a fluororubber dispersion having a solid content concentration of 23.1% by mass. When the copolymer composition of this fluororubber was examined by NMR analysis, it was VdF / HFP = 78/22 (mol%) and the Mooney viscosity (ML _{1 + 10} (100 ° C.)) was 55. This fluororubber is referred to as fluororubber A1.

(Carbon black)
(B1): Seast 6 (ISAF) manufactured by Tokai Carbon Co., Ltd. (N ₂ SA = 119 m ² / g, DBP oil absorption = 114 ml / 100 g)

(Organic amine compound)
(C1): Stearylamine (Farmin 86T) (manufactured by Kao Corporation)

(Crosslinking agent)
(D1): Perhexa 25B (manufactured by NOF Corporation)

(Crosslinking accelerator)
(E1) triallyl isocyanurate (TAIC) (manufactured by Nippon Kasei Co., Ltd.)

(Acid acceptor)
(F1) Zinc oxide (kind) (manufactured by Sakai Chemical Industry Co., Ltd.)

Example 1
Using a kneading machine (MixLabo 0.5L manufactured by Moriyama Co., Ltd., rotor diameter: 6.6 cm, tip clearance: 0.05 cm), the front rotor rotation speed: 60 rpm, the back rotor rotation speed: 50 rpm, and fluorine 100 parts by mass of rubber (A1) is kneaded with 20 parts by mass of carbon black (B1), 0.5 parts by mass of stearylamine (C1) and 1.0 parts by mass of zinc oxide (F1), and a fluororubber precompound (NP) is added. Prepared. The maximum temperature of the discharged kneaded material was 175 ° C.

  When a dynamic viscoelasticity test was performed on the obtained fluororubber pre-compound (NP) using a rubber process analyzer (RPA2000), the difference δG ′ was 602 kPa.

  Using 12 inch mass of the obtained fluororubber pre-compound (NP), an 8-inch open roll (manufactured by Kansai Roll Co., Ltd.), a front roll rotation speed of 21 rpm, a back roll rotation speed of 19 rpm, and a roll gap of 0.1 cm Then, 0.75 parts by mass of perhexa 25B (D1), 0.5 parts by mass of TAIC (E1) and 0.5 parts by mass of stearylamine (C1) were kneaded to prepare a fluororubber full compound (PR). The maximum temperature of the discharged kneaded product was 71 ° C.

  The fluororubber full compound prepared in Example 1 was pressed at 170 ° C. for 30 minutes for crosslinking, and further oven-crosslinked at 200 ° C. for 1 hour to produce a sheet-like test piece having a thickness of 2 mm as a crosslinked product.

With respect to the obtained cross-linked test piece, the tensile strength at break and tensile elongation at 25 ° C. were measured. Further, the tensile breaking strength and tensile breaking elongation at 160 ° C. were measured, and a high temperature tensile repeated test was conducted. The results are shown in Table 1.
Furthermore, the dynamic viscoelasticity measurement of the obtained crosslinked product was performed. The results are shown in Table 1.

Example 2
Using a kneading machine (MixLabo 0.5L manufactured by Moriyama Co., Ltd., rotor diameter: 6.6 cm, tip clearance: 0.05 cm), the front rotor rotation speed: 60 rpm, the back rotor rotation speed: 50 rpm, and fluorine 100 parts by mass of rubber (A1) is kneaded with 20 parts by mass of carbon black (B1), 2.0 parts by mass of stearylamine (C1) and 1.0 part by mass of zinc oxide (F1), and a fluororubber pre-compound (NP) is added. Prepared. The maximum temperature of the discharged kneaded material was 163 ° C.

  When a dynamic viscoelasticity test was performed on the obtained fluororubber pre-compound (NP) using a rubber process analyzer (RPA2000), the difference δG ′ was 525 kPa.

  Using 12 inch parts of the obtained fluororubber pre-compound (NP), an 8-inch open roll (manufactured by Kansai Roll Co., Ltd.), a front roll rotation speed of 21 rpm, a back roll rotation speed of 19 rpm, and a roll gap of 0.1 cm Then, 0.75 parts by mass of perhexa 25B (D1) and 0.5 parts by mass of TAIC (E1) were kneaded to prepare a fluororubber full compound (PR). The maximum temperature of the discharged kneaded product was 70 ° C.

  The fluororubber full compound prepared in Example 2 was pressed at 170 ° C. for 30 minutes for crosslinking, and further oven-crosslinked at 200 ° C. for 1 hour to produce a sheet-like test piece having a thickness of 2 mm as a crosslinked product.

With respect to the obtained cross-linked test piece, the tensile strength at break and tensile elongation at 25 ° C. were measured. Further, the tensile breaking strength and tensile breaking elongation at 160 ° C. were measured, and a high temperature tensile repeated test was conducted. The results are shown in Table 1.
Furthermore, the dynamic viscoelasticity measurement of the obtained crosslinked product was performed. The results are shown in Table 1.

Example 3
Using a kneading machine (MixLabo 0.5L manufactured by Moriyama Co., Ltd., rotor diameter: 6.6 cm, tip clearance: 0.05 cm), the front rotor rotation speed: 60 rpm, the back rotor rotation speed: 50 rpm, and fluorine 100 parts by mass of rubber (A1) is kneaded with 20 parts by mass of carbon black (B1), 0.5 parts by mass of stearylamine (C1), 2.0 parts by mass of zinc oxide (F1), and a fluororubber pre-compound (NP) is added. Prepared. The maximum temperature of the discharged kneaded material was 162 ° C.

  When a dynamic viscoelasticity test was performed on the obtained fluororubber pre-compound (NP) using a rubber process analyzer (RPA2000), the difference δG ′ was 628 kPa.

  Using 12 inch parts of the obtained fluororubber precompound (NP), an 8-inch open roll (manufactured by Kansai Roll Co., Ltd.), a front roll rotation speed of 21 rpm, a back roll rotation speed of 19 rpm, and a roll gap of 0.1 cm Then, 0.75 parts by mass of perhexa 25B (D1), 0.5 parts by mass of TAIC (E1) and 0.5 parts by mass of stearylamine (C1) were kneaded to prepare a fluororubber full compound (PR). The maximum temperature of the discharged kneaded material was 67 ° C.

  The fluororubber full compound prepared in Example 3 was pressed at 170 ° C. for 30 minutes for crosslinking, and further oven-crosslinked at 200 ° C. for 1 hour to produce a sheet-like test piece having a thickness of 2 mm as a crosslinked product.

With respect to the obtained cross-linked test piece, the tensile strength at break and tensile elongation at 25 ° C. were measured. Further, the tensile breaking strength and tensile breaking elongation at 160 ° C. were measured, and a high temperature tensile repeated test was conducted. The results are shown in Table 1.
Furthermore, the dynamic viscoelasticity measurement of the obtained crosslinked product was performed. The results are shown in Table 1.

Example 4
Using a kneading machine (MixLabo 0.5L manufactured by Moriyama Co., Ltd., rotor diameter: 6.6 cm, tip clearance: 0.05 cm), the front rotor rotation speed: 60 rpm, the back rotor rotation speed: 50 rpm, and fluorine 20 parts by mass of carbon black (B1) and 0.5 parts by mass of stearylamine (C1) were kneaded with 100 parts by mass of rubber (A1) to prepare a fluororubber pre-compound (NP). The maximum temperature of the discharged kneaded material was 160 ° C.

  When a dynamic viscoelasticity test was performed on the obtained fluororubber pre-compound (NP) using a rubber process analyzer (RPA2000), the difference δG ′ was 554 kPa.

  Using 12 inch parts of the obtained fluororubber precompound (NP), an 8-inch open roll (manufactured by Kansai Roll Co., Ltd.), a front roll rotation speed of 21 rpm, a back roll rotation speed of 19 rpm, and a roll gap of 0.1 cm Then, 0.75 parts by mass of perhexa 25B (D1) and 0.5 parts by mass of TAIC (E1) were kneaded to prepare a fluororubber full compound (PR). The maximum temperature of the discharged kneaded material was 72 ° C.

  The fluororubber full compound prepared in Example 4 was pressed at 170 ° C. for 30 minutes for crosslinking, and further oven-crosslinked at 200 ° C. for 1 hour to produce a sheet-like test piece having a thickness of 2 mm as a crosslinked product.

With respect to the obtained cross-linked test piece, the tensile strength at break and tensile elongation at 25 ° C. were measured. Further, the tensile breaking strength and tensile breaking elongation at 160 ° C. were measured, and a high temperature tensile repeated test was conducted. The results are shown in Table 1.
Furthermore, the dynamic viscoelasticity measurement of the obtained crosslinked product was performed. The results are shown in Table 1.

Example 5
Using a kneading machine (MixLabo 0.5L manufactured by Moriyama Co., Ltd., rotor diameter: 6.6 cm, tip clearance: 0.05 cm), the front rotor rotation speed: 60 rpm, the back rotor rotation speed: 50 rpm, and fluorine 30 parts by mass of carbon black (B1), 1.0 part by mass of zinc oxide (F1) and 0.5 part by mass of stearylamine (C1) are kneaded with 100 parts by mass of rubber (A1), and a fluororubber pre-compound (NP) is added. Prepared. The maximum temperature of the discharged kneaded material was 208 ° C.

  When the obtained fluororubber pre-compound (NP) was subjected to a dynamic viscoelasticity test using a rubber process analyzer (RPA2000), the difference δG ′ was 1416 kPa.

  Using 13 inches by mass of the obtained fluororubber pre-compound (NP), an 8-inch open roll (manufactured by Kansai Roll Co., Ltd.), a front roll rotation speed of 21 rpm, a back roll rotation speed of 19 rpm, and a roll gap of 0.1 cm Then, 0.75 parts by mass of perhexa 25B (D1), 0.5 parts by mass of TAIC (E1) and 0.5 parts by mass of stearylamine (C1) were kneaded to prepare a fluororubber full compound (PR). The maximum temperature of the discharged kneaded product was 76 ° C.

  The fluororubber full compound prepared in Example 5 was pressed at 160 ° C. for 60 minutes for crosslinking to produce a sheet-like test piece having a thickness of 2 mm as a crosslinked product.

With respect to the obtained cross-linked test piece, the tensile strength at break and tensile elongation at 25 ° C. were measured. Further, the tensile breaking strength and tensile breaking elongation at 160 ° C. were measured, and a high temperature tensile repeated test was conducted. The results are shown in Table 1.
Furthermore, the dynamic viscoelasticity measurement of the obtained crosslinked product was performed. The results are shown in Table 1.

Example 6
In Example 1, a fluororubber pre-compound (NP) was prepared by kneading under the same conditions as in Example 1 except that stearylamine (C1) was not blended in the preparation of the fluororubber pre-compound (NP). The maximum temperature of the discharged kneaded material was 168 ° C.

  When a dynamic viscoelasticity test was performed on the obtained fluororubber pre-compound (NP) using a rubber process analyzer (RPA2000), the difference δG ′ was 405 kPa.

  Using 12 inch parts of the obtained fluororubber pre-compound (NP), an 8-inch open roll (manufactured by Kansai Roll Co., Ltd.), a front roll rotation speed of 21 rpm, a back roll rotation speed of 19 rpm, and a roll gap of 0.1 cm Then, 0.75 parts by mass of perhexa 25B (D1), 0.5 parts by mass of TAIC (E1) and 0.5 parts by mass of stearylamine (C1) were kneaded to prepare a fluororubber full compound (PR). The maximum temperature of the discharged kneaded product was 70 ° C.

  The fluororubber full compound prepared in Example 6 was pressed at 170 ° C. for 30 minutes for crosslinking, and further oven-crosslinked at 200 ° C. for 1 hour to produce a sheet-like test piece having a thickness of 2 mm as a crosslinked product.

With respect to the obtained cross-linked test piece, the tensile strength at break and tensile elongation at 25 ° C. were measured. Further, the tensile breaking strength and tensile breaking elongation at 160 ° C. were measured, and a high temperature tensile repeated test was conducted. The results are shown in Table 1.
Furthermore, the dynamic viscoelasticity measurement of the obtained crosslinked product was performed. The results are shown in Table 1.

Comparative Example 1
Using a kneading machine (MixLabo 0.5L manufactured by Moriyama Co., Ltd., rotor diameter: 6.6 cm, tip clearance: 0.05 cm), the front rotor rotation speed: 60 rpm, the back rotor rotation speed: 50 rpm, and fluorine 20 parts by mass of carbon black (B1) was kneaded with 100 parts by mass of rubber (A1) to prepare a fluororubber pre-compound (NP). The maximum temperature of the discharged kneaded product was 174 ° C.

  When a dynamic viscoelasticity test was performed on the obtained fluororubber pre-compound (NP) using a rubber process analyzer (RPA2000), the difference δG ′ was 453 kPa.

  Using 120.0 parts by mass of the obtained fluororubber precompound (NP), using an 8-inch open roll (manufactured by Kansai Roll Co., Ltd.), the front roll rotation speed is 21 rpm, the back roll rotation speed is 19 rpm, and the roll gap is 0.1 cm. Then, 0.75 parts by mass of perhexa 25B (D1) and 0.5 parts by mass of TAIC (E1) were kneaded to prepare a fluororubber full compound (PR). The maximum temperature of the discharged kneaded product was 70 ° C.

  The fluororubber full compound prepared in Comparative Example 1 was subjected to crosslinking by pressing at 170 ° C. for 30 minutes.

Claims (9)

A method for producing a fluororubber composition, comprising:
The production method includes a step of kneading the fluororubber (A) and the carbon black (B) in the presence of the organic amine compound (C1 ) ,
The maximum temperature Tm of the kneaded product at the time of kneading in the step and the maximum temperature of the kneaded product at the time of discharge are 80 to 220 ° C., respectively.
Carbon black (B) is Ri carbon black der is nitrogen adsorption specific surface area _(N 2 SA) of ^{10 m} 2 / g or more,
The organic amine compound (C1) is selected from the group consisting of a primary amine represented by R ¹ NH ₂ , a secondary amine represented by R ¹ R ² NH, and a tertiary amine represented by R ¹ R ² R ³ N. A fluororubber composition , wherein R ¹ , R ² and R ³ are the same or different and all are alkyl groups having 1 to 50 carbon atoms Manufacturing method. The manufacturing method of Claim 1 which contains 5-50 mass parts of carbon black (B) with respect to 100 mass parts of fluororubbers (A). The carbon black (B) is a carbon black having a nitrogen adsorption specific surface area (N ₂ SA) of 10 to 180 m ² / g and a dibutyl phthalate (DBP) oil absorption of 40 to 180 ml / 100 g. Or the manufacturing method of 2. The fluororubber (A) is a vinylidene fluoride copolymer rubber, a tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer rubber, or a tetrafluoroethylene / propylene copolymer rubber. 4. The production method according to any one of 3 above. The manufacturing method of any one of Claims 1-4 which contain 0.1-10 mass parts of organic amine compounds (C1 ) with respect to 100 mass parts of fluororubbers (A). When the uncrosslinked fluororubber composition is subjected to a dynamic viscoelasticity test using a rubber process analyzer (RPA) (measurement frequency: 1 Hz, measurement temperature: 100 ° C.), the shear elastic modulus G ′ (1 %) And the difference δG ′ (G ′ (1%) − G ′ (100%)) between the shear elastic modulus G ′ (100%) at a dynamic strain of 100% is 120 kPa or more and 3,000 kPa or less. The manufacturing method of any one of 1-5. A cross-linked fluororubber obtained by cross-linking the fluororubber composition obtained by the production method according to claim 1. 8. The fluororubber crosslinking according to claim 7, wherein the loss elastic modulus E ″ is 400 kPa or more and 6000 kPa or less in a dynamic viscoelasticity test (measurement temperature: 160 ° C., tensile strain: 1%, initial load: 157 cN, frequency: 10 Hz). object. The fluororubber according to claim 7 or 8, wherein the storage elastic modulus E 'is 1500 kPa or more and 20000 kPa or less in a dynamic viscoelasticity test (measurement temperature: 160 ° C, tensile strain: 1%, initial load: 157 cN, frequency: 10 Hz). Cross-linked product.